Main  Lib- 


LIBRARY 

OF  THE 

UNIVERSITY  OF  CALIFORNIA. 


GIFT    OF 


Class 


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TY  OF  CALIFORNIA-COLLEGE  OF  AGRICULTURE.! 


AGRICULTURAL  EXPERIMENT  STATION. 
E.  W.  HILGARD,  Director.  BERKELEY,   CAL. 

KESISTANT   VINES- 


SELECTION,   ADAPTATION,   AND  GRAFTING. 


BY   ARTHUR   P.   HAYNE,   Pn.B., 

Assistant  in  Charge  of  Viticulture  and  Olive  Culture. 


APPENDIX     TO     VITICULTURAL     REPORT,     1896. 


SACRAMENTO; 

A.  j.  JOHNSTON,    :    :    :    :    :    SUPERINTENDENT  STATE  PRINTING, 

1897. 


Viticulture, 

Agricultural  Experiment  Station, 
University  of  California. 


Principal   Topics . 


Resistant  Vines.     Qfp.-fc  vo^u^: . Jt&ft  »«?^r  1897 

Vine  Pruning.  Btl.  119  1897 

Death  of  Vines  in  Santa  Clara  •«•  134  1901 

Herbaceous  Grafting.  M  146  1902 

Resistant  Vines  arid  Hybrids.  M  148  1902 

Vine  Diseases  in  Sonoma  w  168  1905 

Selection  of  Vine  Cuttings  Circ.  26  1906 

Grafting  Resistant  Vines.  Bui.  180  1906 

Oidiura  of  the  Vine.  »  186  1907 

Insects  of  the  Vine.  M  192  1907 

Best  Wine  Grapes  M  193  1907 

Pruning  Young  Vines .  M  H  H 

Pruning  Sultaninas  "  M  »» 

Grape  Root  Worm  »•  196  1908 

Resistant  Vines.  M  197  1908 

Vine  Diseases.  ff  "  " 

Grape  Leaf  Hopper  M  198  M 

Grape  Growing  in  Imperial.  ••  210  1911 


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UNIVERSITY  OF  CALIFORNIA-COLLEGE  OF  AGRICULTURE. 

AGRICULTURAL  EXPERIMENT  STATION. 
E.  W.  HILGARD,  Director.  BERKELEY,   CAL. 


EESISTANT   VINES- 


SELECTION,   ADAPTATION,   AND  GRAFTING. 


BY   ARTHUR   P.   HAYNE,   Pn.B., 
Assistant  in  Charge  of  Viticulture  and  Olive  Culture. 


APPENDIX     TO     VITICULTURAL     REPORT,     1896. 


SACRAMENTO; 

A.  j.  JOHNSTON,    :    :    :    :    :    SUPERINTENDENT  STATE  PRINTING. 

1897. 


HE 
UNIVERSITY 

OF 


EXPERIMENT   STATION  AND  SUB-STATIONS  OF  THE 
UNIVERSITY  OF  CALIFORNIA-1895-96. 


CENTRAL  STATION  (Berkeley,  Alameda  County). 

E.  W.  HILGARD,  Ph.D.,  LL.D.  (Professor  of  Agriculture),  Director  and  Chemist. 

E.  J.  WICKSON,  M.  A.  (Associate  Professor  of  Agriculture,  Horticulture,  and  Entomology), 
Superintendent  of  Agricultural  Grounds. 

R.  H.  LOUGHRIDGE,  Ph.D.  (Assistant  Professor),  Agricultural  Geologist  and  Agricultural 

Chemist. 

C.  W.  WOODWORTH,  M.S.  (Assistant  Professor),  Entomologist. 
W.  A.  SETCHELL,  Ph.D.  (Professor  of  Botany),  Botanist. 
M.  E.  JAFFA,  Pb.B.,  M.  S.  (Assistant  Professor  of  Agriculture),  First  Assistant  Chemist 

in  Agricultural  Laboratory. 
ARTHUR  P.  HAYNE,  Ph.B.  (Instructor),  Assistant  in  charge  of  Viticulture  and  Olive 

Culture. 

GEO.  E.  COLBY,  Ph.B.  (Instructor),  Second  Assistant  Chemist  in  Viticultural  Laboratory. 
C.  H.  SHINN,  A.B.,  Inspector  of  Stations. 

F.  T.  BIOLETTI,  B.S.  (Instructor),  Bacteriologist ;  in  charge  of  Viticultural  Cellar. 
EMIL  KELLNER,  Foreman  of  Station  Grounds. 

A.  V.  STUBENRAUCH,  Clerk  to  the  Director. 

SIERRA  FOOTHILL  CULTURE  SUB-STATION  (near  Jackson,  Amador  County). 
R.  C.  RUST,  Patron ;   Jackson. 


-,  Foreman ;  Jackson. 


SOUTHERN   COAST  RANGE  CULTURE  SUB-STATION  (near  Paso  de  Robles,  San 

Luis  Obispo  County). 

F.  D.  FROST,  Patron  ;  Paso  Robles. 

T.  F.  SEDGWICK,  in  charge ;  Paso  Robles. 

SAN    JOAQUIN    VALLEY    CULTURE    SUB-STATION    (near   Tulare  City,  Tulare 

County). 

JOHN  TUOHY,  Patron  ;  Tulare  City. 
JULIUS  FORRER,  Foreman  ;  Tulare  City. 

SOUTHERN  CALIFORNIA  CULTURE  SUB-STATION  (near  Pomona,  Los  Angeles 

County). 

C.  F.  LOOP,  Patron ;  Chino. 

J.  W.  MILLS,  Foreman ;  Pomona. 

CHICO  FORESTRY  SUB-STATION  (near  Chico,  Butte  County). 

R.  F.  PENNELL,  Patron ;  Chico. 
A.  B.  BOLAND,  Foreman ;  Chico. 

SANTA  MONICA  FORESTRY  SUB-STATION  (near  Santa  Monica,  Los  Angeles  Co.). 

ROY  JONES,  Patron ;  Santa  Monica. 
J.H.  BARBER,  Foreman ;  Santa  Monica. 

VITICULTURAL  SUB-STATION  (under  private  auspices). 

EAST  SIDE  SANTA  CLARA  VALLEY  STATION  ;  Mission  San  Jos£,  Alameda  County.    John 
Gallegos,  Patron ;  Mission  San  Jose". 


208859 


TABLE  OF  CONTENTS. 


PAGE. 
INTRODUCTORY  NOTE 8 

PHYLLOXERA:  Natural  habitat;  Evolution  of,  and  resistant  vines;  Introduc- 
tion into  Europe 9 

REMEDIES  FOR  THE  PHYLLOXERA _ 10 

Insecticide:  Extinction  treatment 10 

Submersion:  Nature  of  the  soil;  Depth  and  duration  ;  Dangers _.        11 

Plantations  in  Sand 12 

Resistant  Vines:  Replanting  of  European  vines;  Influence  on  growth  and 
crop ;  Influence  on  quality  of  wine  ;  Extra  expense ;  Discovery  of  the  resist- 
ance of  American  vines ;  First  attempts  at  planting ;  Species  and  varieties  ; 
Vitis  Riparia  and  Rupestris ;  Selection  ;  Cause  of  failure ;  Hybrids  and  direct 

producers;  Standard  of  resistance _ _ 12-22 

Character  of  Lands  for  Resistant  Vines :  Calcareous  soil ;  Compactness ;  Humid- 
ity; Fertility;  Preparation  of  the  ground;  Deep  culture _._  24 

QUARANTINE  AND  DISINFECTION 25 

DESCRIPTION    OF   RESISTANT  VINES— V.  Rupestris;  V.  Riparia;   Lenoir; 

Herbemont;  Solonis;  V.  Doaniana;  V.  Calif ornica;  V.  Arizonica 26 

GRAFTING— Systems  of— English  ;  Cleft ;  Ligatures ;  Time  for  grafting ;  Cutting 

off  of  roots ;  Care  of  grafting  vines ;  Choice  and  preservation  of  scions 37 

Grafting  on  cuttings  ;  Heeling  in ^ 49 

NURSERIES— Choice  and  preparation  of  soils ;  Planting ;  Care  of  ;  Transplanting.  50-54 


ILLUSTRATIONS. 


Photograph  of  non-selected  and  selected  vines  of  the  same  age,  growing  side  by  side 
in  the  vineyard  of  John  Swett,  Martinez,  Cal. 

Fig.  1.  Showing  the  formation  of  callus  on  a  scion  cut  for  a  cleft-graft. 

2.  Stock  and  scion  ready  for  a  whip-graft,  for  grafting  of  cuttings  on  small  vines. 

3.  Manner  of  cutting  scion. 

4.  Respective  positions  of  parallel  cuts  in  scion  and  stock  of  cleft-graft. 
5, 6.  Ordinary  cleft-graft  on  old  vine. 

7.  The  scion  cut  for  a  cleft-graft. 

8.  Manner  of  using  rafna  on  a  cutting  whip-graft. 

9.  Manner  of  using  raffia  when  lead  strips  are  used. 

10.  Nursery  of  grafted  cuttings,  showing  method  of  planting  and  banking. 

11.  A  six-year-old  vine,  badly  grafted,  perishing  from  phylloxera  on  roots  from  scion- 

12.  Old  grafted  vine,  showing  almost  normal  difference  between  size  of  stock  and 

scion. 


INTRODUCTORY  NOTE. 


Owing  to  the  fact  that  the  vineyards  of  a  part  of  the  State  are  being 
destroyed  by  the  phylloxera,  and  that  at  any  moment  the  hitherto 
unaffected  parts  may  become  infected,  it  has  been  deemed  advisable 
to  publish  the  following  bulletin  in  order  to  aid  those  who  are  already 
making  earnest  endeavors  to  replant  their  ravaged  vineyards,  as  well  as 
to  endeavor  to  correct  misconceptions  of  some  fundamental  principles. 

In  this  work  I  have  followed  very  closely  my  answers  to  letters  of 
inquiry  from  the  vineyardists  who  have  written  to  the  University  for 
information,  so  that  the  bulletin  may  be  considered  as  an  answer  to 
actual  questions  asked  by  the  vine-growers. 

I  have  drawn  largely  on  notes  made  from  the  lectures  of  my  former 
instructor,  Professor  Pierre  Viala,  of  PEcole  Nationale  d' Agriculture  de 
Montpellier,  France,  as  well  as  from  the  revision  of  those  lectures  as 
given  in  his  valuable  book  "Adaptation."  All  those  who  read  French 
are  strongly  advised  to  consult  this  work,  as  it  is  complete  scientifically 

as  well  as  practically. 

ARTHUR  P.  HAYNE. 
December,  1896. 


RESISTANT  VINES;  THEIR  SELECTION,  ADAPTATION, 
AND  GRAFTING. 


Natural  Habitat  of  the  Phylloxera. — The  phylloxera  is  a  minute  insect 
that  is  found  on  both  the  leaves  and  roots  of  the  grapevine.  It  causes, 
ultimately,  the  death  of  all  the  varieties  of  the  Vitis  Vinifera,  or 
European  vine,  as  well  as  that  of  many  other  species.  It  is  essentially 
an  insect  of  American  origin,  its  native  habitat  being  that  part  of  the 
United  States  east  of  the  Rocky  Mountains,  below  the  Canada  line;  it 
has  existed  on  the  American  vines  in  that  part  of  the  United  States,  so 
far  as  is  known,  for  ages.  Up  to  a  quite  recent  date,  however,  little  was 
known  of  this  insect,  beyond  a  few  facts  concerning  the  leaf-inhabiting 
form  (sometimes  also  called  the  gall  form),  which,  being  comparatively 
harmless  in  its  effects  on  the  vine,  was  merely  noted  as  a  curiosity. 
Though  having  lived  on  the  American  wild  vines  of  the  East  for  a 
longer  time  than  history  can  record,  nothing  was  known  concerning  its 
deadly  effects  upon  the  non- American  species. 

Evolution  of  Phylloxera  and  Resistant  Vines. — It  would  seem,  from 
geological  specimens  of  extinct  species  of  American  vines,  that,  for  a 
long  time,  there  has  been  a  sort  of  struggle  going  on  between  the 
phylloxera  and  the  wild  vines.  All  weakling  vines  in  the  forests 
perished  from  the  bite  of  the  insect,  while  those  that  were  strong  and 
vigorous  did  not,  but,  in  conformity  with  a  general  law  of  Nature, 
gradually  developed  characteristics  or  qualities  that  enabled  them  to 
withstand  the  attacks  of  the  phylloxera.  Of  course  this  took  a  very 
long  time  to  come  about,  for  such  changes  in  the  nature  of  species  do 
not  take  place  in  a  few  years;  science  shows  that  it  requires  ages  to 
bring  about  such  results.  Hence,  it  is  the  veriest  nonsense  to  speak  of 
"the  root  form  of  the  phylloxera  having  suddenly  come  into  existence 
since  the  use  of  insecticides  on  the  leaves,  being  forced  by  the  poisoning 
of  its  natural  habitat  to  seek  shelter  and  food  on  the  roots."  While  it 
is  perfectly  true  that  the  original  insect  was  probably  a  leaf  insect,  just 
as  the  oak  phylloxera  is  to-day,  yet  it  took  many  ages  to  develop  or 
evolve  the  root-inhabiting  form  from  it. 

Introduction  into  Europe. — Probably  it  would  have  been  many  years 
before  the  complicated  life-history  of  the  phylloxera  would  have  been 
known,  had  it  not  been  for  the  fact  that  by  some  unfortunate  accident 
the  insect  was  carried  beyond  the  Atlantic  and  dropped  among  the 
vineyards  of  the  Old  World.  This  occurred  some  thirty-odd  years  ago. 
Finding  a  new  species  of  grapevine  especially  well  adapted  for  its 
growth  and  development,  it  began  to  multiply  faster  than  it  did  on  the 
wild  vines  of  its  native  forests,  and  soon  caused  the  entire  destruction 
of  some  of  the  finest  vineyards  of  the  Old  World.  For  some  time  the 


10  UNIVERSITY   OF   CALIFORNIA. 

cause  of  the  death  of  the  vines  was  not  suspected;  but  by  an  accident 
the  roots  of  the  sickly  vines  were  found  to  be  covered  with  a  small  in- 
sect, which  was  proved  to  be  identical  with  the  Phylloxera  Vastatrix  of 
America.  At  once  the  search  for  an  economical,  effective  remedy  began. 
Thousands  of  plans  were  proposed  and  tried  by  private  persons  and  Gov- 
ernment commissions;  and  though  many  were  found  that  would  result 
in  the  death  of  the  insect,  yet  either  because  of  economical  reasons,  or 
the  danger  to  the  vine  arising  from  the  quantities  of  the  insecticide, 
none  were  very  generally  adopted  for  the  saving  of  the  vineyards. 


REMEDIES. 

After  a  quarter  of  a  century  of  careful  and  systematic  study  and 
experiment,  it  has  been  found  possible  to  combat  the  phylloxera  by 
means  of :  (a)  Insecticides,  (b)  Submersion,  (c)  Planting  in  Sand,  (d)  Re- 
sistant Vines. 

INSECTICIDES. 

The  only  two  insecticides  that  have  proved  at  all  practical  are  Carbon 
Bisulphid  and  Sulfocarbonate  of  Potassium.  These  are  either  injected 
into  the  soil  around  the  vine,  killing  the  insect  by  the  vapor,  or  they  are 
carried  into  the  soil  dissolved  in  water,  as  is  the  case  with  the  sulfocar- 
bonate;  in  some  cases  the  carbon  bisulphid  is  mixed  by  "  injectors " 
with  the  water  and  carried  into  the  soil.  It  is  perfectly  true  that  when 
these  insecticides  are  properly  applied  under  favorable  conditions,  the 
phylloxera  will  be  almost  entirely  exterminated.  It  is  also  a  fact,  how- 
ever, that  owing  to  the  light  doses  that  have  to  be  applied  on  account  of 
the  danger  to  the  roots  of  the  vine,  these  treatments  with  insecticides 
must  be  given  annually.  This  heavy  annual  expense,  then,  makes  insecti- 
cides economically  practicable  only  on  the  most  valuable  vineyards, 
such  as  those  that  produce  the  finest  "  chateau  "  wines. 

Extinction  Treatment. — In  California,  with  the  present  state  of  the 
market,  insecticides  are  entirely  too  expensive  to  be  thought  of  as  a 
permanent  thing,  though  they  may  be  useful  in  cases  where  it  is  desired 
to  kill  every  living  thing,  insect  or  vegetable,  in  a  small  spot  of  a  vine- 
yard that  has  just  been  infected.  By  promptly  tearing  out  the  diseased 
vines  as  soon  as  a  few  become  infected,  the  spread  of  the  phylloxera 
may  be  checked  for  a  long  time.  This  treatment  "by  extinction"  has 
been  very  successful  in  checking  the  rapidity  of  the  spread  of  the 
phylloxera  in  several  countries  where  it  has  been  systematically  used. 
The  most  striking  examples  are  found  in  Switzerland.  It  is  now  being 
rigorously  applied  in  the  Champagne  region  of  France,  and  though  no 
hope  is  entertained  of  being  able  to  preserve  the  vineyards  for  all  time, 
yet  it  is  certain  that  their  ultimate  destruction  will  be  delayed  very 
many  years. 

It  is  a  grave  mistake  to  allow  the  phylloxera  to  remain  undisturbed 
till  it  has  destroyed  the  entire  vineyard.  A  great  many  years  may  be 
added  to  the  productiveness  of  an  infected  vineyard,  if  the  diseased  vines 
be  torn  out  as  soon  as  they  show  the  effects  of  the  insect.  This  tearing- 
out  of  the  sick  vines  should  be  done,  even  if  the  soil  be  not  treated  with 
insecticides.  If  nothing  else  be  done,  the  vines  should  be  carefully 


RESISTANT    VINES;     THEIR   SELECTION,    ADAPTATION,    ETC.  11 

rooted  out  and  burned  on  the  spot,  the  ground  around  being  covered  lightly 
with  straw  or  brush,  which  is  immediately  burned,  so  as  to  destroy  all 
insects  that  may  be  on  or  near  the  surface  of  the  soil,  or  on  the  roots 
and  trunks  of  the  vines.  Aside  from  this  use  of  insecticides  for  pur- 
poses of  the  eradication  of  the  insect  from  a  small  spot,  it  is  far  too 
expensive  an  operation  to  be  relied  on  in  this  State,  with  any  known 
insecticide. 

While  none  have  thus  far  been  found  that  are  economical,  it  is  by  no 
means  certain  that  the  time  will  not  come  when  we  may  have  a  cheap 
and  effective  insecticide  for  our  phylloxera-infected  vineyards.  But  the 
public  is  warned  against  trusting  to  seductive  advertisements  of  those 
who  claim  to  have  infallible  remedies.  The  field  has  been  so  carefully 
worked  by  the  best  chemists,  entomologists,  and  practical  vineyardists  of 
the  world,  that  there  is  little  probability  of  anything  effective  being  dis- 
covered very  soon.  But  even  though  a  very  cheap  insecticide  be  found, 
it  must  not  be  forgotten  that  this  must  be  applied  annually,  and  no 
matter  how  slight  the  expense,  this  annual  treatment  merely  means  a 
diminished  net  revenue.  Perhaps  one  of  the  commonest  deceptions 
practiced  by  the  sellers  of  phylloxera  remedies  is  the  use  of  powerful 
fertilizers  mixed  with  some  so-called  insecticide.  By  this  means  it  is 
certain  that  the  vine  may  be  temporarily  revived,  but  the  revival  is  too 
short-lived  to  be  depended  on  for  crops  enough  to  pay  for  the  treatment, 
which  amounts  simply  to  a  heavy  fertilization. 

SUBMERSION. 

Much  misconception  has  arisen  concerning  the  utility  of  this  opera- 
tion. While  it  is  perfectly  true  that,  under  certain  special  conditions, 
it  is  effective  and  economical,  yet  the  conditions  under  which  submer- 
sion is  possible  are  so  special  that  but  few  can  avail  themselves  of  this 
means  of  combating  the  phylloxera. 

Nature  of  the  Soil. — In  the  first  place,  the  vineyard  must  be  perfectly 
or  almost  level,  and  in  easy  communication  with  an  abundant  water- 
supply.  Then,  the  soil  must  be  neither  too  porous  nor  too  compact. 
Again,  the  submersion  must  be  continuous,  and  not  interrupted,  even 
for  an  hour.  Should  the  surface  of  the  soil  be  exposed  for  an  hour 
at  the  end  of  forty  days  in  a  vineyard  that  requires  a  sixty-day  sub- 
mersion, the  forty  days  of  submersion  do  not  count,  but  the  whole 
operation  has  to  be  begun  as  though  there  had  never  been  a  day  of 
•submersion.  We  give  below  a  table  illustrating  some  of  the  special 
conditions  that  have  to  be  fulfilled  in  order  to  make  this  seemingly 
simple  operation  possible  and  practically  effective.  This  is  dwelt  upon 
somewhat  at  length,  as  the  Station  is  in  receipt  of  numerous  inquiries 
on  this  subject  from  those  who  imagine  that  mere  heavy  irrigation  will 
be  effective  in  checking  the  phylloxera. 

Depth  and  Duration. — In  all  cases  where  the  loss  of  water  per  day, 
either  on  account  of  the  permeability  of  the  soil  or  the  evaporation,  or 
both,  amounts  to  more  than  500  cubic  yards  per  day  on  an  acre, 
submersion  becomes  impossible. 


12  UNIVERSITY   OP    CALIFORNIA. 

Time  Required  to  kill  Phylloxera  in  a  vineyard  by  Submersion  in  Water. 


Duration  of 

submersion. 

Loss  per  Acre  of 
Water    in   24 

Days  in  Autumn. 

Days  in  Winter. 

Hours. 

Very  slightly  permeable  soils 
Medium  permeable  soils    

50  to  55 
55  to  60 

55  to  60 
60  to  65 

40  cu.  yds. 
40  to  120  cu.  yds. 

Permeable  soils                 ..        

65  to  70 

70  to  75 

120  to  280  cu.  yds. 

Very  permeable  soils 

90 

90 

390  to  450  cu.  yds. 

From  the  table  it  will  be  seen  that,  with  the  necessity  of  Continuous 
submersion  from  1  to  2  feet,  the  operation  is  not  so  simple  as  many  sup- 
pose. It  will  not  do  to  leave  too  much  of  the  trunk  of  the  vine  or  canes 
exposed  above  the  water-level.  Hence  it  is  that  in  the  case  of  high- 
pruned  vines  the  depth  of  the  water  must  be  greater  than  in  the  case 
of  short-pruned  vines.  The  duration  of  the  submersion  depends,  to  a 
certain  extent,  upon  the  climate.  In  very  cold  countries  the  duration  of 
the  complete  submersion  may  be  considerably  shortened.  The  table  is 
given  for  warm  or  temperate  climates,  such  as  that  of  California. 

Dangers  of  Submersion. — It  is  to  be  remarked  that  submerged  vines 
speedily  perish  from  "  black  knot."  "gouty  swellings,"  etc.;  besides  such 
vines  are  extremely  sensitive  to  the  attacks  of  the  "powdery  mildew" 
and  other  fungous  diseases.  It  may  be  added  that  heavier  fertilization 
is  required  on  vineyards  that  are  submerged  than  otherwise  would  be 
the  case. 

PLANTING    IN    SAND. 

In  this  case,  too,  it  is  to  be  noted  that  a  merely  "sandy  soil,"  as  is 
generally  understood  by  the  term  in  this  State,  is  not  sufficient  to  check 
the  spread  or  development  of  the  phylloxera.  There  must  be  at  least 
85%  of  pure  sand  in  a  soil  that  is  to  be  relied  on  as  a  phylloxera- 
proof  soil.  But  even  this  high  percentage  of  sand  is  not  sufficient,  if 
there  be  a  slight  admixture  of  clay.  More  or  less  lime  does  not  make 
much  difference.  It  has  been  found  that  while  the  Vitis  Vinifera  will 
grow  well  in  sandy  soils  of  the  above  description,  yet  they  require  heavy 
fertilization  and  yield  crops  of  an  inferior  quality,  though  heavy 
quantity. 

RESISTANT   VINES. 

It  being,  then,  not  economical,  except  in  very  special  cases,  to  attempt 
to  destroy  the  phylloxera  itself,  we  are  inevitably  driven  to  the  con- 
clusion that  all  of  our  vineyards  on  non-resistant  roots  will  sooner  or 
later  perish  under  the  attacks  of  the  insect.  We  can,  however,  replant 
the  vineyard  on  roots  that,  while  tolerating  the  insect,  suffer  nothing  or 
little  from  its  bites.  This  is  the  only  reliable  measure  thus  far  found  to 
be  of  practical  value  to  those  who  would  grow  grapes.  While  it  involves 
the  loss  of  capital  expended  in  a  growing  vineyard,  it  enables  us  for 
the  future  to  guard  against  further  loss  from  the  same  cause;  and,  in  the 
case  of  new  plantations,  it  shuts  out  the  occurrence  of  the  loss. 

Replanting  of  European  Vines. — It  is  mere  folly  to  plant  the  Vitis 
Vinifera,  on  its  own  roots,  in  vineyards  where  the  phylloxera  has  already 
destroyed  the  vines.  While  it  is  possible  for  a  full-grown,  healthy 


RESISTANT    VINES;     THEIR    SELECTION,    ADAPTATION,    ETC.  13 

Vinifera  to  resist  the  attacks  of  the  phylloxera  for  several  years  before 
perishing,  it  is  not  possible  for  a  young,  partly  rooted,  non-resistant 
vine  to  live  any  length  of  time  when  planted  in  soil  that  is  already 
infected  with  the  insect  and  somewhat  exhausted  from  years  of  cultiva- 
tion. Some  imagine  that  it  would  be  economical  to  plant  the  Viniferas 
in  the  same  place  that  the  dead  vine  occupied,  expecting  to  get  two  or 
three  crops  from  the  vine  before  it  perishes.  This  is  a  common  error 
in  countries  infected  with  the  phylloxera,  especially  at  the  beginning  of 
the  trouble.  It  has  been  tried  over  and  over  again  in  all  the  countries 
where  the  vineyards  have  been  destroyed,  and,  even  with  many  pre- 
cautions, such  as  allowing  the  land  to  rest  for  several  years,  etc.,  it  has 
ahuays  proved  a  heavy  financial  loss,  even  in  the  richest  soils  and  with 
the  most  vigorous  varieties. 

I  do  not  know  of  a  single  case,  out  of  the  great  number  of  experiments 
of  this  sort,  that  has  not  proved  disastrous  from  a  financial  standpoint, 
even  in  countries  where  the  value  of  the  crop  is  greater  than  in  Cali- 
fornia. The  difference  in  cost  between  planting  on  resistant  roots  and 
planting  on  non-resistant  roots  is  so  insignificant  that,  taken  with  the 
certainty  of  having,  sooner  or  later,  to  go  through  the  same  operation  of 
replanting,  renders  planting  non-resistants  a  most  foolish  thing  to  do. 

Influence  on  Growth  and  Crop. — It  is  to  be  noted,  too,  that  when  a 
Vinifera  has  been  grafted  on  a  variety  of  resistant  vine,  perfectly  adapted 
to  soil,  climate,  stock,  etc.,  it  will  produce  heavier  crops,  sweeter  and  better- 
matured  grapes,  of  larger  size,  than  the  Vinifera  would  produce  on  the  same 
soil  were  there  no  phylloxera  at  all.  This  alone,  aside  from  the  certain  loss 
of  capital  in  the  future,  would  more  than  pay  for  the  extra  expense  of 
planting  on  resistant  roots.  When  it  is  observed  that  a  vineyard 
planted  on  resistant  vines  does  not  produce  fully  as  much  as  the  same 
varieties  did  under  similar  circumstances  on  non-resistant  roots,  the 
conclusion  must  be  that  it  is  not  the  fault  of  the  resistant  itself,  but  that 
the  wrong  adaptation  to  soil,  etc.,  has  been  made,  just  as  would  obtain  if 
the  wrong  variety  of  Vinifera  were  planted  on  the  same  soil.  Failures, 
then,  in  plantations  on  resistant  roots  merely  show  that  the  vine-grower 
has  made  a  mistake  which  he  can  rectify  by  the  exercise  of  a  due  amount 
of  study  and  intelligence. 

Influence  on  Quality  of  Wine. — It  was  for  a  long  time  asserted  that 
the  wine  made  from  Viniferas  grafted  on  the  resistant  stock  was  of 
inferior  quality,  or  would  in  time  acquire  some  of  the  disagreeable 
characteristics  of  the  American  grape.  Time  has  proved  that  the  qual- 
ity of  the  wine  is  only  affected  in  so  far  that  perfectly  matured  grapes 
give  a  better  product  than  those  imperfectly  matured;  and  as  the  grapes 
from  grafted  vines  are,  as  a  rule,  better  matured  than  is  usually  the 
case  on  non-resistants,  the  results  are  in  favor  of  the  grafted  vine.  It  is 
also  to  be  noted  that  grafted  vineyards  are  less  apt  to  coulure,  or  the 
dropping  of  the  young  grapes. 

Extra  Expense  of  Resistant  Stock. — It  is  true  that  the  resistant  vines 
require  more  care  to  get  them  started  than  the  Viniferas,  and  therein  lies 
one  of  the  heaviest  counts  against  the  use  of  resistant  stock.  The  extra 
time  and  expense  of  grafting  and  cultivation  before  the  vineyards  pay 
are  certainly  drawbacks;  but  as  things  stand  to-day,  he  who  would  have 
a  vineyard  must  encounter  resolutely  such  extra  care  and  expense,  or 
leave  the  field  for  some  one  else  who  is  willing  to  do  the  work  properly. 


14  UNIVERSITY    OF    CALIFORNIA. 

Discovery  of  the  Resistance  of  American  Vines. — When  the  phylloxera 
was  first  found  on  the  vines  of  the  Old  World,  some  profound  thinkers 
proposed  grafting  the  Vitis  Vinifera,  or  European  grape,  on  the  Ameri- 
can stocks,  arguing  very  correctly  that,  as  the  phylloxera  had  existed 
from  all  time  on  the  wild  American  vines,  there  must  be  some  quality 
in  these  vines  that  enabled  them  to  resist  the  attacks  of  the  insect;  for 
there  were  the  wild  vines  thriving  in  the  forests  with  the  phylloxera  on 
them  to  prove  it.  Examination  showed  that,  in  Europe,  on  vineyards 
attacked  by  the  phylloxera,  wherever  there  was  an  American  vine  it 
alone  out  of  all  the  vines  did  not  seem  to  be  affected  with  the  deadly  dis- 
ease that  was  sweeping  out  of  existence  millions  of  dollars'  worth  of 
capital.  Some  of  these  vines  had  been  grafted,  and  it  was  found  that 
they  gave  abundant  and  excellent  crops  where  the  Viniferas  perished. 
No  sooner  was  this  exemption  of  American  vines  observed,  than  the 
more  progressive  vine-growers  sent  to  America  for  cuttings  and  seeds  of 
the  American  vines  that  were  found  growing  wild  in  the  forests.  It 
would  be  impossible  to  estimate  the  number  thus  imported  into  the 
European  vineyards,  but  there  were  very  many  shiploads  of  them. 

First  Attempts  at  Planting  Resistant  Vines. — Tens  of  thousands  of 
acres  were  planted  out  in  American  vines,  but  the  results  were  at  first 
disappointing.  Many  were  found  to  perish  outright,  others  eked  out  a 
feeble  existence  and  finally  died  even  before  grafting,  while  some  throve 
at  first  and  even  for  a  short  time  after  grafting,  and  then  perished. 
Among  all  these  some  were  noted  that  from  the  first  flourished  most 
exceptionally,  and,  after  grafting,  yielded  heavier  crops  than  had  ever 
been  obtained  with  Viniferas  on  the  same  soil. 

Species  and  Varieties. — This  caused  close  attention  to  be  paid  to  the 
species  and  varieties  of  the  American  vines.  After  a  due  amount  of 
study  and  experiment,  it  was  found  that  in  America,  instead  of  having 
a  single  species,  as  in  Europe,  we  have  eighteen  distinct  specieSj  grouped 
as  follows: 

Section    I.    MUSCADINIA  (Planchon). 

Vitis  Rotundifolia  (Michaux). 
Vitis  Munsoniana  (Simpson). 

Section  II.    EUVITIS  (Planchon). 
1st  Series.    LABRUSC.E. 

Vitis  Labrusca  (Linneeus). 

2d  Series.    LABRUSCOIDE^E. 

Vitis  Californica  (Bentham). 
Vitis  Caribaea  (de  Candolle). 
Vitis  Coriacea  (Schuttle worth). 
Vitis  Candicans  (Engelmann). 

3d  Series.    AESTIVALES. 

Vitis  Lincecumii  (Buckley). 
Vitis  Bicolor  (Le  Conte). 
Vitis  Aestivalis. 

4th  Series.   CINERASCENTES. 

Vitis  Berlandieri  (Planchon). 
Vitis  Cordifolia  (Michaux). 
Vitis  Cinerea  (Engelmann). 

5th  Series.    RUPESTRES. 

Vitis  Rupestris  (Scheele). 

Vitis  Monticola  (Buckley). 

Vitis  Arizonica  (Engelmann). 
6th  Series.    RIPARIA. 

Vitis  Riparia  (Michaux). 

Vitis  Rubra  (Michaux). 


RESISTANT    VINES  J     THEIR   SELECTION,    ADAPTATION,    ETC.  15 

From  this  list,  with  its  grouping,  it  will  be  found  that  the  question 
of  American  vines  is  a  far  more  complicated  one  than  at  first  might 
appear,  especially  if  it  is  borne  in  mind  (and  too  great  stress  cannot  be 
laid  upon  the  fact)  that  each  of  these  eighteen  species  embraces  many 
hundreds  of  varieties,  these  varieties  differing  the  one  from  the  other  in 
the  same  species  as  much  as  the  "  Zinfandel "  does  from  the  "  Seedless 
Sultana."  The  Vitis  Vinifera,  or  the  single  species  of  Europe,  which 
furnishes  us  with  our  wine-  and  most  of  our  table-grapes,  has  over  1,500 
varieties.  It  is  possible  that  there  will  be  found  almost  as  many  varie- 
ties of  each  one  of  the  eighteen  American  species  in  America.  In  the 
case  of  the  Vinifera,  however,  we  have  the  grape  berries  to  help  us 
classify  the  varieties.  With  the  American  resistants  we  can  place  little 
reliance  on  the  berries,  as  many  of  them  are  not  eatable,  and  in  a  vine- 
yard the  leaf  alone  is  seen  for  but  a  year  or  so;  and  after  that  it  is  cut 
back  and  grafted.  Hence  the  difficulty  in  getting  the  average  vine- 
grower  to  familiarize  himself  with  the  variations  in  species  and  varieties 
of  American  resistants.  This  explains  how  so  many  very  intelligent 
vine-growers  continually  confuse  species  and  variety. 

This  confusion  of  species  with  variety  has  proved  the  greatest  stumbling- 
block  in  the  path  of  the  modern  viticulturist.  The  inability,  or  in  many 
cases  the  unwillingness,  to  recognize  the  fact  that  there  are  hundreds  of 
varieties  of  Riparias,  etc.,  and  that  some  are  valuable  and  others  are 
not,  has  cost  the  world  vast  sums  of  money  and  has  driven  many  vine- 
growers  into  bankruptcy.  The  burden  fell  heaviest  on  the  French,  who 
were  the  first  to  seriously  take  up  resistants.  They  have  had  many 
years  of  experience  on  a  large  scale,  and  we  are  able  to  profit  by  their 
mistakes  and  successes  in  planting  out  our  resistant  vineyards.  At 
least  we  should  do  so;  but  it  is  unfortunately  true  that  to-day  in  this 
State  there  are  very  many  who  simply  refuse  even  to  investigate  what 
others  have  done.  Local  experience  is  necessary,  no  doubt;  but  unless 
it  is  intelligently  directed,  vast  sums  must  first  be  spent  before  any 
adequate  results  are  to  be  had.  When  certain  facts  have  been  estab- 
lished in  many  countries  beyond  a  possibility  of  doubt,  it  is  folly  for  us 
to  disregard  them.  I  have  found  that  when  the  experience  of  others  is 
alluded  to  it  is  very  often  sneeringly  thrust  aside,  with  the  remark  that 
"We  do  things  differently  in  California."  Just  as  though  "doing 
things  differently"  could  change  a  thin-wooded,  weak  variety  into  a 
thick-wooded,  vigorous  one.  It  really  would  seem  that  many  of  the 
vine-growers  of  this  State  are  disposed  to  begin  experimenting  with 
resistants  precisely  as  the  Europeans  did,  making  the  same  costly  mis- 
takes and  utterly  disregarding  the  successes  in  the  way  of  improved 
varieties,  already  achieved. 

When  the  Europeans  found  that  some  of  their  imported  American 
cuttings  did  well,  while  others  perished,  they  took  one  step  in  the  right 
direction  by  recognizing  the  fact  that  there  were  really  material  differ- 
ences existing  between  American  vines.  Their  scientists  told  them  the 
names  of  the  species,  and  pointed  out  the  fact  that  each  species  embraces 
many  different  varieties.  The  vineyardists,  however,  were  in  such  haste 
to  replant  their  ruined  vineyards  that  they  grasped  at  the  names  of 
species,  and  paid  but  little  attention  to  the  subdivisions  of  each  group. 
By  a  system  of  experimental  selection  they  found  that  the  Vitis  (species) 
Riparia  and  the  Vitis  Rupestris  were  the  best  all-around  groups  to  select 
from.  The  other  species  were  found  to  be  of  little  or  no  practical  value, 


16  UNIVERSITY    OF    CALIFORNIA. 

on  account  of  their  difficulty  of  adapting  themselves  to  new  conditions, 
refusal  to  grow  from  cuttings,  or  requiring  such  special  soils,  etc.,  that  it 
was  not  practically  possible  to  use  them.  Hence  the  sixteen  other  species 
of  American  vines  will  not  now  be  considered  at  this  time,  reserving  for 
another  place  and  time  a  full  discussion,  from  a  scientific  standpoint,  of 
these  species  which  have  but  little  practical  interest  for  us  to-day.  Let 
the  reader  be  assured  that  it  will  be  idle  for  him  to  attempt  to  improve 
on  the  Riparia  and  Rupestris,  except  by  years  of  hybridizing,  or  repro- 
duction by  layering,  which  is  far  too  long  and  expensive  an  operation, 
except  for  public  experiment  stations  or  fancy  vineyardists.  A  few  of 
the  hybrids  already  made  will,  in  their  place,  be  discussed. 

Vitis  Riparia  and  Vitis  Rupestris. 

As  soon  as  the  fact  was  established  that  the  Vitis  Riparia  and  Vitis 
Rupestris  were  more  valuable  than  the  rest  of  the  eighteen  species,  the 
European  growers  did  exactly  as  is  being  done  to-day  in  California. 
They  sent  to  the  American  forests  and  got  any  and  everything  that 
could  be  called  Riparia  or  Rupestris.  Perhaps  one  of  the  most  striking 
mistakes  they  made  was  to  attempt  to  reproduce  the  resistant  stocks 
from  seeds.  This  proved  a  most  dismal  failure  everywhere,  for  almost 
every  seedling  developed  into  a  new  variety  of  more  or  less  worthless- 
ness,  it  being  seldom  that  a  grape  seedling  is  as  good  as  the  mother- 
vine.  The  well-meant  advice  of  some  "to  go  slow"  was  disregarded, 
and  they  planted  anything  they  could  get.  The  result  was  that  tens  of 
thousands  of  acres  had  to  be  dug  up,  after  several  years  of  waiting. 
Then  came  the  period  of  doubt,  and  the  revival  of  the  old  question, 
"  Do  resistants  really  resist?" 

In  this  State,  similarly,  many  entertain  serious  doubts  on  this  subject. 
Mysterious  diseases  are  reported  that  attack  one  man's  vines  and  leave 
his  neighbors'  intact.  In  some  cases  a  man's  Riparias  are  found  to  be 
partly  perishing,  while  others,  bought  from  a  different  nursery,  are  doing 
finely.  All  this  was  passed  through  by  the  European  vine-growers 
years  ago,  and  it  cost  them  roundly;  but  they  persevered  and  -finally 
triumphed  over  all  obstacles,  in  spite  of  having  far  more  difficulties  to 
contend  with  than  their  California  brethren  have.  By  visiting  their 
neighbors,  and  the  government  experiment  stations,  they  profited  by  the 
lessons  each  had  learned  under  different  conditions,  and  thus  it  came 
about  that  even  the  laborers  soon  learned  to  become  comparative  experts 
in  American  ampelography. 

There  seems  to  be  a  deep-seated  objection  on  the  part  of  many  Cali- 
fornia growers  to  going  into  what  they  are  pleased  to  call  "useless 
details."  They  want  a  hard-and-fast  rule  that  will  fit  all  cases,  and 
that  will  not  require  any  study  on  their  part.  The  moment  it  is  sug- 
gested that  there  are  varieties  of  Riparia  or  Rupestris,  they  become 
impatient  and  say  "  That's  all  well  enough  for  the  experts,  but  there  is 
not  time  for  such  details."  Yet  it  became  necessary  that  the  most  igno- 
rant peasants  abroad  should  familiarize  themselves  with  these  details 
before  the  vineyards  were  sucessfully  reconstituted;  and  they  did  so, 
becoming  most  expert  observers  and  invaluable  aids  to  those  more  deeply 
.versed  in  the  science.  Instead  of  relying  on  nurserymen  to  do  the 
selecting  for  them,  they  procured  from  those  that  had  the  best  varieties 
and  propagated  their  own  nursery  stock,  carefully  rejecting  all  weak 


RESISTANT    VINES;    THEIR    SELECTION,    ADAPTATION,    ETC.  17 

vines,  or  such  as  did  not  seem  to  thrive  as  well  as  others  on  their  special 
soil.  It  was  not  a  case  with  them  of  refusing  to  "  send  their  money  out 
of  the  country11  in  order  to  procure  for  propagating  purposes  the  very 
best  to  be  had,  as  is  unfortunately  the  case  with  many  here  in  California. 
They  did  want  the  best  to  be  had,  knowing  full  well  that  it  was  false 
economy  to  get  inferior  stocks  when  better  could  be  procured,  even  at  a 
higher  price.  The  patronage  of  "home  products"  is  perfectly  right 
when  the  products  are  as  good  as  can  be  had  elsewhere,  but  when  applied 
to  inferior  nursery  stock,  it  is  going  rather  too  far. 

Selection  is  the  great  lesson  that  has  been  learned  in  the  planting  of 
resistant  vines.  Now  in  order  to  select  the  best  to  be  had,  one  may  have 
to  go  beyond  his  own  vineyard  into  other  vineyards,  even  if  they  be 
situated  on  the  other  side  of  the  world.  If  he  cannot  go  personally,  he 
can  at  least  rely  on  some  one  in  whom  he  has  confidence,  who  can;  and 
when  once  he  has  a  few  vigorous  vines  he  can  soon  propagate  enough 
for  himself  and  his  neighbors. 

In  selecting  varieties  it  was  found  that  the  geographical  analogies 
between  the  native  habitat  of  the  vine  and  that  of  the  place  where  it 
was  to  grow  had  little  to  do  with  the  problem.  What  was  needed  was 
a  variety  that  was  very  vigorous  and  large-wooded,  and  that  was  easily 
suited  to  new  soils  and  conditions.  It  is  to  be  remarked  that  among 
the  many  species  and  their  varieties,  some  are  very  hard  to  transplant 
into  other  conditions,  while  others  adapt  themselves  very  readily  to  new  condi- 
tions. Concerning  species  it  has  been  found  that  the  Riparia  and 
Rupestris,  as  groups,  adapt  themselves  more  readily  to  changed  condi- 
tions than  any  of  the  other  American  species  known. 

It  is  perfectly  true,  however,  that  the  varieties  of  each  of  these  species 
differ  greatly  the  one  from  the  other  in  this  respect.  There  are  some 
Riparia  varieties  which  it  seems  almost  impossible  to  grow  successfully, 
except  under  most  exceptional  conditions.  There  are  otjier  Riparia 
varieties  that  do  remarkably  well  in  the  same  soils  in  which  other 
varieties  of  the  same  species  refuse  absolutely  to  grow.  Yet  in  both 
cases  they  are  "true  Riparias."  The  expression  "true  Riparias"  is 
used  advisedly,  for  one  of  the  commonest  questions  the  Department  is 
asked  is,  "Where  can  I  get  a  '  true  Riparia"?"  The  point  to  be  made  is 
that  there  are  hundreds  of  "  true  Riparias  "  that  are  worthless.  What  has 
been  said  in  this  connection  of  the  Riparia  holds  good  in  the  case  of  the 
Varieties  of  the  Vitis  Rupestris. 

After  some  years  of  experiment  it  was  found  that  the  Vitis  Riparia 
was  the  best  all-around  group  for  the  majority  of  European  soils.  This 
is  shown  from  the  fact  that  to-day,  out  of  the  2,500,000,000  of  vines 
grafted  on  resistant  stocks  in  the  Old  World,  probably  1,700,000,000  are 
grafted  on  Riparias.  The  remainder  are  almost  all  Rupestris  stocks, 
with  some  of  the  best  hybrids  that  the  Americans  had  previously  secured. 

While  the  Riparia  is  beyond  a"  doubt  the  best  species  for  the  average 
European  vineyard  land,  it  by  no  means  follows  that  the  same  is  true 
in  California.  In  Europe  there  are  abundant  summer  rains,  except  in 
the  hottest  parts.  With  the  thorough  cultivation  given  to  the  soil,  the 
Riparias  thrive  remarkably  well,  for  there  is  always  sufficient  moisture 
in  the  soil  to  keep  up  the  growth  of  the  vine.  In  California,  on  the 
other  hand,  there  is  little  or  no  summer  rain  and  in  almost  all  of  our 
vineyards  the  soil  dries  out  to  a  considerable  depth.  As  the  Riparia,  as 
a  group,  is  naturally  shallow-rooted,  the  state  of  affairs  in  California  be- 
2— RV 


18  UNIVERSITY    OF    CALIFORNIA. 

comes  very  different  from  that  on  the  other  side  of  the  ocean.  Instead  of 
being  the  species  that  one  should  at  once  choose,  as  a  general  proposition, 
it  becomes  the  species  that  one  should  not  choose  until  careful  investiga- 
tion has  been  made  as  to  the  depth,  moisture,  and  richness  of  the  soil.  If 
there  is  sufficient  natural  richness,  moisture,  and  coolness  in  the  soil  to 
keep  the  shallow-growing  roots  of  the  Riparia  in  good  condition  all  the 
year  round,  then  it  is  undoubtedly  the  species  to  choose.  If  there  is 
any  doubt  about  the  moisture,  coolness,  and  friability  of  the  soil,  then 
the  Rupestris  becomes  the  species  to  choose  in  all  cases,  except  where 
there  is  an  excess  of  moisture,  lime,  or  compactness.  The  reason  for  this  is 
that  the  Rupestris  is  a  species  that  grows  naturally  in  dry  soils,  and  sends 
its  roots  downward  more  than  the  Riparia.  It  will  thrive  in  a  soil  that 
is  so  dry  that  any  Riparia  would  inevitably  perish.  If  one  will  take  the 
trouble  to  dig  out,  with  care,  a  Riparia  vine  that  grows  side  by  side 
with  a  Rupestris  of  the  same  age  in  a  somewhat  dry  soil,  he  will  at  once 
perceive  the  difference  in  the  manner  of  root-growth  in  each  case. 

Cause  of  Failures. — While  it  is  true  that  most  of  the  replanted  vine- 
yards in  California  have  been  reconstituted  with  Riparia  stock,  it  is 
also  true  that  there  have  been  many  failures;  and  doubtless  many  of 
the  failures  thus  far  noted  can  be  attributable  to  the  selection  of  the 
wrong  species  for  the  given  soil.  In  many  cases  it  has  been  found  that 
Riparias  have  thriven  remarkably  well  on  dry,  steep  hillsides,  and  this 
has  been  advanced  as  an  argument  against  the  idea  that  Riparias  require 
moist  soils.  In  some  of  the  cases  that  have  been  called  to  the  attention 
of  the  Department  it  has  been  found,  on  investigation,  that  the  so-called 
Riparia  stock  was  not  Riparia  at  all,  but  Rupestris  that  had  been  sold 
by  the  nurserymen  as  Riparia,  either  ignorantly  or  because  the  pur- 
chaser wanted  Riparias.  While  this  explanation  holds  good  in  some 
cases,  there  are  others  where  it  will  not,  and  seemingly  dry  hillsides  are 
keeping  Riparias  in  a  remarkably  thriving  condition.  In  these  cases  it  has 
been  found  that,  although  the  vineyard  was  on  a  hillside  that  seemed  dry, 
yet  in  reality  there  was  an  underdrainage  near  the  surface  that  supplied 
the  Riparias  with  ample  moisture,  the  soil  being  quite  fertile.  By  inves- 
tigating closely  enough  there  will  always  be  found  explanations  of  the 
seeming  anomalies,  that  in  no  way  shake  the  truth  of  the  general  rule. 
Exceptions  must  be  taken  into  consideration  and  looked  out  for  with  the 
greatest  care. 

Another  cause  of  failure  in  soils  that  to  all  appearance  are  "  Riparia 
soils  "  is  that  the  land  was  not  in  proper  condition  when  the  stocks  were 
planted.  It  has  already  been  remarked  that  the  resistant  vines  require 
far  greater  care  in  planting  than  is  usually  given  to  the  Vinifera.  The 
most  important  point  is  the  proper  preparation  of  the  soil  before  plant- 
ing. It  has  been  established,  beyond  the  possibility  of  rational  doubt, 
that  before  planting  American  vines  'the  land  should  be  given  one 
plowing  that  is  twice  as  deep  as  would  have  been  necessary  had  Vini- 
feras  been  planted  in  the  usual  manner.  This  is  one  of  the  practical 
lessons  learned  abroad.  One  of  the  vineyards  that  is  used  by  the  Pro- 
fessors of  the  National  School  of  Agriculture  in  France  as  the  most 
striking  illustration  of  the  necessity  of  deep  plowing,  is  situated  on  the 
banks  of  the  river  Herault,  on  the  very  best  "  Riparia  soil "  in  France. 
When  first  replanted  in  resistant  stocks  no  deeper  plowing  than  had 
been  given  for  the  Viniferas  was  thought  necessary.  A  very  large  vine- 


RESISTANT   VINES)    THEIR   SELECTION,    ADAPTATION,    ETC.  19 

yard  was  planted  to  Riparias.  After  several  years  it  was  found  that 
they  seemed  to  be  total  failures.  As  the  soil  was  a  typical  Riparia  soil, 
and  the  variety  used  was  the  very  best,  much  interest  was  aroused. 
After  consultation,  it  was  decided  to  dig  out  the  entire  vineyard,  give  it 
a  very  deep  plowing,  and  replant  it  with  cuttings  from  the  same  mother- 
vines  that  had  supplied  the  cuttings  for  the  original  plantation.  This  was 
done,  and  to-day  there  is  not  a  finer  vineyard  in  the  country.  Experi- 
ence has  shown  that  all  American  resistants  require  deep  plowing  at  first, 
though  some  do  not  require  quite  as  deep  preparation  as  others.  The 
Riparias  are  the  most  exacting  in  this  respect.  It  is  a  safe  rule  to  follow, 
that  the  drier  and  poorer  the  soil  the  greater  care  should  be  taken  to  prepare 
it  for  the  reception  of  American  resistant  vines. 

Hybrids  and  Direct  Producers. — Thus  far  only  the  pure  species, 
unmixed,  have  been  spoken  of,  but  there  are  many  vines  of  more  or  less 
value  that  are  not  pure  species,  but  have  been  produced,  artificially 
or  accidentally,  by  cross  fertilization,  or  by  mixing  the  pollen  of  the 
flowers  of  two  or  more  species;  so  that  the  resulting  vine  has  some  of 
the  characteristics  of  each  of  the  parent  vines.  The  Americans  have 
made  the  greatest  progress  in  the  hybridization  of  their  vines;  owing  to 
the  fact  that  in  the  East  the  Vitis  Vinifera  cannot  be  grown,  they  were 
forced  to  improve  the  wild  vines,  so  as  to  have  table  and  other  grapes 
for  their  own  use.  Lately  the  French  have  taken  up  the  hybridization 
of  vines,  and  made  remarkable  progress.  The  great  object  at  present  is 
to  obtain  a  vine  that,  while  resisting  the  phylloxera,  the  two  mildews, 
the  black  rot,  etc.  (all  of  which  diseases  are  natives  of  America,  and 
which  the  American  vines  resist  more  or  less  well),  will  give  without 
grafting  a  grape  that  has  size,  and  the  quantity  and  quality  of  the  Vitis 
Vinifera.  The  American  grapes  have  all  more  or  less  of  a  peculiar  charac- 
teristic musky  flavor  (generally  called  "foxy  taste"),  that,  while  more 
or  less  agreeable  for  table-grapes,  becomes  unpalatable  when  fermenta- 
tion has  vinified  the  must.  What  is  wanted  is  a  vine  that  will  have  all 
the  qualities  of  the  American  vine  as  regards  the  growth,  but  all  of  the 
qualities  of  the  European  vine  as  regards  the  quantity  and  excellence  of 
the  crop.  Thus  far  the  goal  has  not  been  reached;  but  in  some  cases 
there 'have  been  approaches  to  it.  At  times  the  "direct  producer"  (a 
vine  possessing  the  resisting  power  in  its  roots  and  free  from  unpleasant 
flavors)  has  been  favorably  spoken  of,  and  in  some  cases  many  thou- 
sands of  acres  were  planted  with  them,  but  extended  trial  proved  that 
they  were  not  to  be  compared  with  the  Vinifera  grafted  on  a  resistant 
stock.  As  an  example  of  this  may  be  cited  the  Lenoir,  or  "Jacquez  "  as 
it  is  known  in  Europe.  At  one  time  it  was  extensively  planted  as  a 
direct  producer,  but  it  was  found  that  the  crops  were  unprofitable,  on 
account  of  small  quantity  and  the  inferior  quality  of  the  wine;  so  it  was 
relegated  to  the  place  of  a  grafting  stock.  It  was  found,  however,  that 
as  a  stock  it  could  not  compare  with  the  selected  "  standards,"  Riparia 
and  Rupestris,  because  after  grafting  it  lost  much  of  the  vigor  that  made 
it  remarkable  when  ungrafted;  besides  which  it  is  more  difficult  to  prop- 
agate from  cuttings.  The  same  can  be  said  of  most  of  the  hybrids  of 
Vinifera  with  American  vines.  They  seem  to  lose  to  a  great  extent 
their  vigor  when  grafted,  and  even  when  ungrafted  they  do  not  possess 
the  same  degree  of  resistance  to  the  phylloxera  as  the  mother-vine  from 
which  the  resisting  qualities  were  derived;  and  it  is  seldom  that  they 


20  UNIVERSITY   OF    CALIFORNIA. 

are  entirely  free  from  the  "  foxy  "  flavor  of  the  American  vine,  though 
when  properly  adapted  they  are  very  vigorous  and  thick-wooded,  which 
causes  many  to  prefer  them  to  poor  varieties  of  Riparia  and  Rupes- 
tris.  Among  the  best-known  hybrids  we  may  mention  York-Madeira, 
Catawba,  Taylor,  Vialla,  Lenoir,  Doaniana,  Norton's  Virginia,  Autuchon, 
Isabella,  etc. 

While  it  is  not  claimed  that  the  time  will  not  come  when  some  perfect 
hybrids  may  be  found  that  will  give  all  the  qualities  desired  either  for  a 
stock  or  direct  production,  it  is  certainly  true  that  thus  far  none  have  been 
found  the  use  of  which  is  as  satisfactory  as  grafting  the  selected  varieties 
of  the  pure  species.  It  would  seem  from  the  results  thus  far  obtained  that 
the  perfect  hybrid  stock  may  be  looked  for  long  before  the  perfect  direct 
producer  is  found.  The  former  are  greater  successes  in  their  way  than 
the  latter  have  been.  Investigation  will  show  that  most  of  the  favorable 
reports  concerning  new  hybrids  emanate  from  nurserymen  or  interested 
parties,  and  hence  must  be  taken  cum  grano  sails. 

Many  Americans  have  been  misled  by  reading  scraps  from  foreign 
literature  concerning  resistants.  Thus  one  very  common  error,  so  origi- 
nated, in  this  State  is  that  certain  varieties  "  require  calcareous  soils."  As 
a  general  statement  it  is  true  that  all  American  vines  dislike  strongly  cal- 
careous soils,  though  some  will  stand  them  better  than  others.  In  France 
the  soils  are,  as  a  rule,  far  more  calcareous  than  those  of  this  State.  The 
fact  that  the  American  vines  "  fear  lime  "  has  caused  the  vineyardists 
there  great  trouble  in  reconstituting  their  vineyards.  In  fact,  there  are 
certain  regions,  such  as  the  Cognac  region  of  France,  where  it  has  been 
found  almost  impossible  to  make  either  the  Riparia  or  Rupestris  grow 
in  some  of  the  most  famous  vineyards  of  the  region.  So  refractory  have 
most  of  the  American  vines  proved  that  the  main  hope  there  now  seems 
to  lie  in  the  planting  of  the  Vitis  Berlandieri  of  Texas,  by  means  of 
layers,  for  it  will  not  grow  from  cuttings. 

Whenever  Europeans  are  reported  as  experimenting  with  varieties 
other  than  the  standard  Riparia  or  Rupestris,  it  is  safe  to  conclude  in 
most  cases  that  the  soil  is  excessively  calcareous. 

STANDARDS    OF    RESISTANCE. 

It  must  be  remembered  that  mere  resistance  to  phylloxera  is  not  the 
only  desideratum  in  determining  the  value  of  a  resistant  stock.  There 
must  be,  with  the  exemption  from  the  effects  of  the  phylloxera,  a 
natural  adaptability  to  soil  and  climate  that  will  enable  the  vine  to  be 
sufficiently  vigorous  to  support  the  graft  with  a  sufficient  amount  of  sap  to 
produce  and  nourish  properly  a  large  crop. 

Nodosities  and  Tuberosities. — A  nodosity  is  the  swelling  on  the  very 
young,  tender  rootlets  of  the  grapevine,  resulting  from  the  sting  of  the 
phylloxera.  It  is  the  mildest  form  of  the  injury  to  a  root  of  the  vine 
that  is  noticeable  to  the  examiner.  The  mere  presence  of  a  few  of  these 
nodosities  on  the  roots  of  a  vine  does  not  indicate  that  the  vine  is  not 
a  valuable  resistant.  In  fact,  there  are  but  few  of  the  American  resistant 
vines  on  which  nodosities  are  not  found.  While  it  shows  that  the  resist- 
ance of  the  vines  is  not  the  maximum,  it  by  no  means  indicates  that 
the  vine  is  not  (on  account  of  its  ready  adaptability)  the  very  vine  for 
the  given  soil.  These  nodosities  are  whitish  or  pinkish,  and  resemble 
somewhat  the  head  and  neck  of  a  long-billed  bird.  The  insect  causing 


RESISTANT   VINES;    THEIR   SELECTION,   ADAPTATION,    ETC.  21 

the  swelling  is,  as  a  rule,  to  be  found  in  the  acute  angle  formed  where 
the  head  joins  the  neck,  or  in  other  words,  on  the  throat.  There  may 
be  a  number  of  insects  found  on  a  nodosity,  but  the  insect  whose  bite 
caused  the  swelling  will  be  found  in  this  acute  angle.  If,  however, 
cancerous  patches  of  decomposition  are  found  on  the  more  fully 
developed  roots,  something  more  serious  is  threatened,  namely  a  tuber- 
osity.  This  indicates  that  the  resistance  of  the  vine  is  less  than  was 
the  case  where  only  nodosities  were  found.  Wherever  tuberosities  are 
found  there  also  are  nodosities,  but  the  reverse  is  not  true.  It  is  cus- 
tomary to  judge  of  the  resistance  of  a  vine  by  the  nature,  number,  and 
position  of  the  tuberosities  on  the  roots.  When  tuberosities  are  found 
that  produce  only  a  wound,  with  a  scab-like  covering  of  cork,  which 
may,  when  dry,  be  scaled  off  with  the  finger-nail,  there  is  a  very 
high  resisting  power;  as  the  cancers  become  deeper  seated  and  as  they 
appear  more  numerous  on  the  older  roots,  the  moare  does  the  resisting 
power  of  the  vine  fall. 

In  order  to  be  able  to  indicate  with  some  degree  of  definiteness  the 
resistance  to  the  phylloxera  (not  the  value  as  a  stock),  an  arbitrary 
scale  has  been  provisionally  adopted  by  the  scientists  and  practicians 
of  the  entire  viticultural  world.  In  this  scale  the  maximum  of  resist- 
ance is  taken  as  20,  and  the  minimum  as  0.  Thus,  the  resisting 
power  of  the  best  Riparia  is  indicated  by  19.50,  and  that  of  the  Lenoir 
(a  hybrid)  as  12,  the  best  Rupestris  varieties,  19.50,  etc. 

From  this  it  will  be  seen  that  the  injury  the  phylloxera  does  to  the 
vine  is  not  the  loss  of  sap,  for  that  is  infinitesimal,  but  the  decay  of  the 
roots,  thus  depriving  the  vine  of  its  supply  of  nourishment.  Also,  that 
if  an  old,  vigorous  vine  be  attacked,  it  may  take  many  years  to  destroy 
the  roots,  they  being  very  large  and  well  developed;  and  the  vine  will 
endeavor  to  throw  out  new  roots  as  fast  as  the  old  ones  become  enfeebled. 
With  a  young  vine,  on  the  contrary,  the  root-system  is  not  large,  and 
the  cancers  speedily  so  wreck  the  root- system  that  it  cannot  support  the 
life  of  the  vine. 

Examples  of  Resistant  Standards. — The  importance  of  the  fact  was 
strongly  impressed  upon  the  writer  from  personal  observation  of  the 
instance  given  by  Prof.  Pierre  Viala,  of  the  Institut  Agronomique, 
France,  in  his  excellent  work  on  "Adaptation."  In  a  collection  of 
American  vines  at  the  National  School  of  Agriculture,  of  Montpellier, 
in  one  of  the  worst  parts  of  the  plot,  there  are,  side  by  side,  their  roots 
interlacing,  some  Rupestris,  Solonis,  Cornucopia,  etc.  The  Rupestris 
shows  but  few  nodosities,  no  tuberosities  at  all,  and  its  resistance  may 
be  indicated  by  the  figure  18  out  of  a  possible  20.  The  Solonis,  besides 
a  great  number  of  nodosities,  shows  on  the  older  roots  a  number  of 
tuberosities  not  very  dangerous  in  appearance,  which  seldom  reach  as 
far  as  the  main  roots.  Its  resistance  is  indicated  by  the  number  15. 
The  roots  of  the  Cornucopia  are  covered  with  large  nodosities  and 
tuberosities  very  prominent  in  character,  and  give  a  resistance  of  4. 

These  were  planted  sixteen  years  ago.  If  the  phylloxera  were  the  only 
factor  in  the  problem,  their  exterior  vegetation  should  indicate  18:15:4. 
As  a  matter  of  fact,  however,  the  reverse  is  the  case.  The  Rupestris, 
upon  which  the  phylloxera  causes  no  damage  whatever,  is  stunted  and 
yellow  and  almost  in  a  dying  condition,  so  that  its  exterior  vegetation 
may  be  described  by  2  out  of  a  possible  20.  The  Solonis,  although 


22  UNIVERSITY   OF    CALIFORNIA. 

suffering  slightly  from  the  attacks  of  the  phylloxera,  is  less  feeble  than 
the  Rupestris,  and  its  growth  can  be  fairly  indicated  by  4  out  of  a  possi- 
ble 20.  The  Cornucopia,  on  the  contrary,  though  badly  attacked  by  the 
phylloxera,  is  comparatively  vigorous,  its  exterior  growth  being  equal  to 
about  15  out  of  a  possible  20.  This  same  anomaly  is  noted  in  the  case 
of  other  vines,  such  as  the  Othello,  Autuchon,  Canada,  etc.,  which,  even 
though  badly  attacked  by  the  phylloxera,  sometimes  do  better  than  the 
Rupestris,  Riparia,  etc.,  of  higher  absolute  resistance  on  certain  soils. 

CHARACTER    OF    LAND    FOR    RESISTANT   VINES. 

The  question  then  presents  itself  to  the  vine-grower:  Given  a  certain 
soil  and  climate,  what  resistant  stock  should  be  chosen?  For  it  is,  at 
this  state  of  knowledge  of  the  phylloxera,  sheer  folly  to  attempt  to  plant 
out  a  vineyard  of  non-resistant  roots  in  place  of  one  that  has  already 
been  destroyed  by  the  insect.  It  is  very  true  that  to-day  there  are  many 
vine-growers,  who,  while  expecting  sooner  or  later  to  lose  their  vine- 
yards, labor  under  the  delusion  that  they  can  get  several  crops  before 
the  phylloxera  destroys  their  second  planting.  This  has  been  tried  the 
world  over,  and  also  in  this  State,  and  in  every  case  has  proved  a  bad 
failure.  If  any  one  is  going  to  plant  a  vine,  let  him  plant  one  that  will 
not  have  to  be  replaced  in  the  course  of  three  or  four  years.  He  will 
have  other  enemies  enough  to  contend  with  without  laying  himself  open 
to  one  of  the  most  terrible  of  insect  pests  known. 

In  silicious  clay  soils  that  contain  but  a  moderate  amount  of  lime,  all 
of  the  American  vines  will  thrive  more  or  less  well.  They  present  in  their 
development,  fructification,  etc.,  certain  differences  which  it  behooves 
one  to  keep  in  mind.  Not  that  in  such  soils  they  would  prove  a  com- 
plete failure;  but  as  the  cost  of  planting  a  vineyard  is  great,  it  is  very 
necessary  to  take  into  consideration  all  the  requirements  and  adapta- 
tions of  each  one,  in  order  to  obtain  the  best  possible  results  instead  of 
merely  fair  ones.  In  other  words,  the  question  is  whether  we  shall  do 
the  best  that  nature  permits,  or  be  content  with  a  great  deal  less  than 
another  man  gets  with  the  same  effort. 

Excessively  Calcareous  Soils. — In  soils  in  which  the  lime  is  largely  in 
excess,  things  are  different.  Here  nearly  all  the  American  vines,  and 
even  some  varieties  of  the  Vitis  Vinifera,  behave  badly.  Observation 
and  experience  have  established  the  fact  that  for  every  soil  there  exists 
an  American  vine  that  will  produce  better  results  than  any  other,  and 
it  should  be  the  endeavor  to  find  it  in  order  to  get  the  best  results  from 
the  soil,  for  it  is  just  as  expensive  to  plant  a  poor  vine  as  a  perfect  one. 
Whatever  be  the  conditions  in  wine-making  to-day,  the  time  will  surely 
come  when  the  industry  will  be  profitable  only  to  those  who  get  the 
maximum  returns  from  their  vines,  and  it  is  beyond  all  dispute  that 
those  who  have  planted  inferior  stocks  cannot  attain  this  end.  They 
will,  when  competition  with  properly  planted  vineyards  begins,  be  driven 
out  of  business,  so  that  the  sooner  this  state  of  affairs  is  duly  appre- 
ciated, the  sooner  wine-making  in  California  will  be  established  on  a 
sound  basis. 

As  has  been  shown,  it  is  established  beyond  possibility  of  rational 
doubt,  that  the  soil  is  one  of  the  principal  factors  in  the  problem  of 
reconstituting  vineyards  destroyed  by  the  phylloxera. 


RESISTANT   VINES;    THEIR   SELECTION,    ADAPTATION,    ETC.  23 

As  regards  soils  designated  as  silicious  clays  or  loams,  all  that  is  to 
be  considered  is  their  compactness,  humidity,  and  fertility.  The  impor- 
tance lies  in  physical  effects  produced  by  a  greater  or  less  admixture  of 
sand,  clay,  etc.,  thus  giving  greater  or  less  compactness,  etc. 

Silicious  sands  containing  a  quantity  less  than  8%  of  clay,  are  classed 
as  "light  soils."  The  Vitis  Vinifera,  or  European  vine,  does  well  in 
such  soils,  without  attaining  extraordinary  development;  it  may  be 
said  to  develop  normally.  This  is  not  the  case  with  the  American  vines, 
however.  Some  few  American  resistants,  hybrids  or  otherwise,  such  as 
the  Lenoir,  Herbemont,  Vialla,  Rupestris,  St.  Georges,  etc.,  produce  in 
them,  in  France,  a  vegetation  that  leaves  little  to  be  desired;  while  the 
Riparia  and  some  others  give  but  a  feeble  growth. 

Compactness. — The  compactness  of  the  soil  is  due  sometimes  to  an 
excess  of  clay,  sometimes  to  an  excess  of  fine  silicious  sand.  In  the 
last  case,  when  the  amount  of  clay  is  less  than  5%  or  6%,  the  soil  is 
excessively  hard  and  compact  after  the  dry  weather  sets  in;  so  much  so 
that  the  roots  of  the  vine  have  great  difficulty  in  penetrating  the  soil, 
and  the  whole  vine  thrives  badly.  An  excess  of  clay  would  seem  to  be  less 
harmful  than  an  excess  of  fine  silicious  sand  or  silt.  Too  great  com- 
pactness of  the  soil  is  a  serious  drawback  to  the  well-being  of  the  vine, 
which,  like  many  other  plants,  prefers  a  friable,  light,  warm  soil;  and 
the  results  obtained  are  more  satisfactory  in  proportion  as  these  condi- 
tions are  more  perfectly  realized.  It  is  true  that  while  some  of  the 
resistants  will  grow  in  the  most  compact  soils,  yet  they  never  attain 
their  maximum  vigor;  while  the  life  of  the  vine  is  notably  shortened. 
In  such  cases  the  American  vines  behave  somewhat  as  do  the  Viniferas; 
but  some  among  them  would  seem  to  resist  such  soils  more  than  others. 
Thus,  the  Riparia  and  the  Rupestris  do  very  poorly  in  compact  soils, 
while  the  Lenoir,  the  Herbemont,  and  the  Vialla  accommodate  them- 
selves better  to  such  conditions.  Each  of  these  vines  will  be  discussed 
more  fully  from  this  point  of  view,  but  the  reasons  for  these  differences 
will  be  given  here;  it  does  not  suffice  merely  to  note  facts,  the  causes 
and  general  results  must  be  looked  for. 

The  Riparias  and  the  greater  part  of  the  Rupestris  varieties  have 
sparse  root-systems,  with  slender  roots;  but  these  roots  are  very  hard  and 
much  ramified,  being  terminated  by  an  abundant  growth  of  very  tena- 
cious root  hairs.  The  Lenoir,  the  Vialla,  the  Herbemont,  the  Cunning- 
ham, the  Cinerea,  the  York-Maderia,  etc.,  have,  on  the  contrary,  larger 
and  stronger  roots  with  less  root  hairs  on  them.  The  Vitis  Vinifera 
and  Lenoir,  vines  that  thrive  so  well  on  all  kinds  of  soils,  have  also 
quite  large,  thick  roots.  Just  why  the  vines  having  the  thickest  and 
fleshiest  soft  roots  should  seem  to  penetrate  more  readily  into  very 
hard,  compact  soils  than  those  with  slim,  slender,  very  hard  roots,  is 
not  fully  understood  as  yet.  It  may  be  that  the  greater  strength  of  the 
larger  roots  enables  them  to  force  their  way  into  compact  subsoils  by 
sheer  force  of  weight  or  mass.  But  whatever  be  the  true  cause,  the  fact 
remains  constant  and  deserves  to  be  noted.  It  shows  that  the  American 
species,  pure  or  hybridized  among  themselves  (such  hybrids  are  called 
Americo-American,  while  those  that  are  hybridized  with  the  Vitis  Vini- 
fera are  called  Franco-American,  the  French  having  made  the  most 
complete  study  of  them  thus  far),  as  well  as  the  Franco- American 
hybrids,  which  inherit  strength  and  size  of  root  from  the  Vitis  Vinifera, 


24  UNIVERSITY    OF    CALIFORNIA. 

will  develop  vigorously  in  compact  soils,  as  they  have  a  powerful  root- 
system.  Years  of  experiment  have  established  this  fact  beyond  the 
possibility  of  dispute. 

Humidity. — The  humidity  of  the  soil  exercises  considerable  influence 
upon  the  vegetation  of  the  vine.  An  excess  of  humidity  is  very  favor- 
able for  the  development  of  fungous  diseases,  coulure,  etc.;  besides  this, 
it  checks  the  proper  development  of  the  root-system.  Plants  growing 
in  a  very  moist  soil  frequently  seem  to  give  a  more  luxurious  external 
vegetation  than  those  growing  on  drier  soils.  In  such  cases  the  root- 
system  is  always  more  feeble  than  would  have  been  the  case  had  the  soil 
been  less  moist.  This  phenomenon  is  not  peculiar  to  the  vine,  but  is 
observed  with  all  plants.  The  root-system  is  always  more  developed  in 
dry  soils  (without  excess,  of  course),  because  of  the  vine  being  forced  to 
seek  moisture  at  a  greater  depth.  It  would  seem,  therefore,  that  in  dry 
soils  such  as  may  be  said  to  be  characteristic  in  the  majority  of  Califor- 
nia vineyards,  the  root-system  must  be  very  well  developed,  as  its 
enfeeblement  counts  heavily  against  the  plant.  It  is,  therefore,  apparent 
that  on  the  dry  soils  of  this  State  vines  should  be  planted  whose  resist- 
ance to  the  phylloxera  is  above  the  average.  This  consideration  is 
independent  of  other  complicating  considerations.  For  dry,  gravelly, 
or  sandy  soils  only  such  species  must  be  chosen  as  give  a  high  resisting 
power  and  well-developed  root-systems. 

An  excess  of  water  in  the  soil  presents  another  difficulty.  Young 
vines  planted  under  such  conditions  will  scarcely  root  at  all,  and  though 
they  may  give  at  first  seemingly  a  good  top-growth,  yet  when  dry 
weather  comes  they  generally  perish  or  suffer  to  such  an  extent  that  it 
is  impossible  to  get  from  them  normal  results. 

Humidity  acts  frequently  in  conjunction  with  compactness,  as  it  does 
with  coldness,  of  the  soil.  The  latter,  however,  generally  is  the  result 
of  the  two  former.  This  combination  of  compactness,  humidity,  and 
coldness  of  the  soil  will  delay  the  starting  of  the  growth  in  spring,  and 
thus  injure  the  timely  nourishment  power  of  the  vine. 

Fertility. — Fertility  is  a  powerful  adjunct  of  the  proper  vegetation  of 
all  plants;  the  more  fertile  a  soil  is,  the  better  will  be  the  vegetation 
thereon.  However,  very  great  fertility  of  the  soil  is  not  necessary  for 
all  kinds  of  American  vines.  The  Rupestris  is,  perhaps,  the  species 
which  thrives  the  best  in  poor  soils,  especially  if  tending  to  dryness.  It 
attains  considerable  dimensions  and  supports  the  graft  very  well  under 
conditions  in  which  other  vines  would  scarcely  grow  at  all.  The  Riparia 
is  far  more  exacting  in  this  respect.  The  Lenoir  and  Herbemont 
accommodate  themselves  very  well  to  poor  soils. 

Such  are  the  principal  conditions  which  influence  the  vegetation  and 
development  of  the  vine  in  the  generality  of  soils,  such  as  are  to  be  dealt 
with  in  this  State.  As  has  been  said,  it  will  not  be  profitable  to  compli- 
cate the  study  of  the  adaptation  of  resistants  in  this  State  at  the  present 
time,  with  the  numberless  exceptions  that  arise  when  one  has  to  deal 
with  soils  in  which  there  is  a  large  excess  of  lime.  There  are  few  such 
soils  in  the  viticultural  regions,  so  the  consideration  of  these  complica- 
tions will  be  deferred  to  a  more  profitable  time. 

The  general  considerations  given  above  are,  of  course,  easily  modified 
to  suit  particular  cases.  Lightness  of  the  soil  and,  in  consequence,  permea- 


RESISTANT    VINES;    THEIR   SELECTION,    ADAPTATION,   ETC.  25 

bility,  being  necessary  for  the  proper  vegetation  of  the  vine;  exceedingly 
deep  plowing,  green  or  straw  manuring,  etc.,  may  be  made  to  sensibly 
modify  the  compactness  and  coldness.  Drainage  will  be  the  remedy  in 
cases  of  too  great  moisture,  while  moderate  irrigation  with  good  cultivation 
will  supply  any  deficiency  in  moisture.  In  all  cases,  however,  it  is  to  be 
noted  that  too  great  care  in  the  cultivation  of  the  soil  cannot  be  given. 
It  is  a  sad  fact  that  in  California,  with  its  mostly  rich,  friable  soils  and 
exceptionally  good  agricultural  machinery,  vineyardists  very  t>ften 
shamefully  neglect  the  cultivation  of  their  vineyards,  and  then  complain 
because  the  results  hoped  for  do  not  materialize.  There  are  far  too  many 
viticulturists  (and  horticulturists,  too)  who,  even  in  heavy  soils,  attempt 
to  make  one  shallow,  ill-timed  plowing  do  for  the  whole  season.  Others 
there  are  who  attempt  to  make  irrigation  take  the  place  of  cultivation. 
There  are  on  record  at  the  Experiment  Station  cases  where  some  very 
fine  orchards  and  vineyards  have  perished  from  this  cause.  There  are 
others  where  the  vines  died  merely  from  drying-out,  due  to  poor  cultiva- 
tion. Some  seem  to  imagine  that  the  cultivation  of  the  soil  that  might 
be  suitable  for  an  old,  thrifty  vineyard  will  be  equally  well  suited  to 
a  very  young  one,  forgetting  that  the  very  young  vines  have  but  a 
very  small  root-system  developed  as  yet.  Some  of  the  reported  failures 
of  resistant  stocks  have  been  found  to  be  due  purely  to  this  cause. 

Preparation  of  the  Ground. — Here,  again,  attention  must  be  called  to 
a  fact  that  has  been  well  established  the  world  over;  namely,  that  all 
American  vines  must  have  deeper  and  better  cultivation  in  starting  than 
the  Vitis  Vinifera,  or  European  vine.  This  is  not  a  theory,  but  a  fact 
too  well  established  under  the  greatest  variety'of  conditions  to  be  con- 
troverted. There  are  in  this  State  some  striking  examples  of  the  good 
effect  of  extra  deep  plowing  before  planting  out  American  vines. 

Too  great  stress  cannot  be  laid  on  this  necessity  of  deep  preparatory 
plowing.  Especially  is  this  necessary  in  California  on  lands  that,  while 
not  being  especially  dry,  are  apt  to  dry  down  considerably  in  summer. 
It  is  especially  necessary  with  the  Riparias  and  those  resistant  vines 
that  tend  to  throw  out  their  roots  horizontally,  instead  of  downward,  as 
is  the  case  with  the  Rupestris.  But  even  the  Rupestris  requires  deep 
plowing  in  order  to  give  it  a  good  start.  Professor  Viala  says  that 
very  deep  plowing  of  land  destined  to  be  planted  in  American  vines  will 
advance  crop-bearing  from  one  to  two  years;  and  the  facts  certainly  bear 
out  this  statement.  Those  who  cannot  give  their  vineyard  land  a  plow- 
ing twice  as  deep  as  is  usually  given,  no  matter  what  be  the  fertility  of 
the  soil,  are  advised  not  to  plant  American  vines,  or  any  other  kind. 

QUARANTINE    AND    DISINFECTION. 

From  what  has  been  said  in  this  connection,  as  well  as  under  the  head 
of  submersion,  it  will  be  seen  in  what  a  "fool's  paradise"  those  are 
dwelling  who,  on  slightly  sandy  soils  well  mixed  with  clay,  say  that 
they  "  have  nothing  to  fear  from  the  phylloxera  "  when  it  reaches  them, 
as  it  surely  will,  sooner  or  later.  There  are  many  regions  of  this  State, 
as  yet  uninfected  with  the  phylloxera,  where  irrigation  is  extensively 
practiced,  and  where  the  soils  are  more  or  less  of  a  sandy  nature.  The 
vine-growers  of  these  regions  refuse  to  believe  that  they  have  anything 
to  fear.  They  may  rest  assured  that  they  have  no  ground  for  such 


26  UNIVERSITY   OF    CALIFORNIA. 

hope,  and  at  the  same  time  are  recommended  to  place  all  possible  safe- 
guards around  their  vineyards  in  the  way  of  quarantine  regulations. 
In  this  way  they  can  delay  the  advent  of  the  phylloxera,  but  cannot 
hope  to  be  free  from  it  forever.  While  the  winged  form  of  the  phyl- 
loxera is  rare  in  California,  it  is  a  fact  that  it  does  exist;  and  hence 
there  is  no  possibility  of  the  insect  becoming  extinct,  as  is  claimed  by 
some.  The  winged  form  is  not  the  one  most  dangerous  for  infection, 
except  in  adjoining  vineyards  with  no  trees  or  hills  between.  Infection 
of  regions  generally  is  due  to  the  gall  form  or  the  root  form,  or  the  eggs 
of  one  or  both.  Hence,  too  great  care  cannot  be  taken  in  avoiding  the 
introduction  of  undisinfected  cuttings,  boxes,  packing  material,  etc.,  on 
which  the  insects  or  their  eggs  might  find  a  lodging-place.  Cuttings 
can  readily  be  thoroughly  disinfected,  while  it  is  almost  impossible  to 
sufficiently  disinfect  rooted  vines  without  destroying  the  greater  part  of 
them. 

The  sooner  the  vine-growers  who  have  not  yet  the  phylloxera  in  their 
vineyards  make  up  their  minds  that  it  is  but  a  question  of  time  before 
they  will,  and  act  accordingly,  the  better  it  will  be  for  them.  It  was 
disregard  of  such  warnings  that  caused  the  backward  state  of  affairs 
existing  in  the  regions  now  being  replanted  in  this  State. 


DESCRIPTION    OF    RESISTANT    VINES. 
VITIS   RUPESTRIS. 

General  Characteristics. — This  species  gives  a  vigorous,  bushy  vine, 
with  a  short,  thick,  strong  trunk;  wood  of  the  year  (one  year  old)  is 
dark  reddish-brown,  sometimes  clear,  shiny,  chestnut-colored;  tendrils 
are  discontinuous.  The  leaves  when  young  are  transparent  and 
brilliant,  and  of  a  russet  red;  when  old  they  are  small,  wider  than  long, 
not  lobed,  and  are  folded  together  so  as  to  form  a  gutter,  glabrous  and 
thick.  The  sinus  of  the  petiole  is  open  and  scarcely  perceptible;  it  has 
well-marked,  wide,  obtuse-teeth  serration.  The  upper  surface  is  deep 
green  and  shiny,  lower  surface  is  of  a  clearer  varnished  green.  Bunch 
small,  with  small,  spherical,  violet-black  berries,  the  interior  of  which  is 
highly  colored.  The  roots  are  long,  slender,  and  very  hard,  but  some- 
times large  and  fleshy,  as  is  the  case  with  the  "Rupestris  du  Lot." 

Varieties. — The  varieties  of  the  Vitis  Rupestris  are  very  numerous. 
Mr.  H.  Jaeger,  who  was  the  first  to  study  the  variations  of  the  wild 
Rupestris,  has  succeeded  in  isolating  over  a  hundred  types.  Millardet 
was  the  first  to  call  attention  to  the  great  value  of  the  Rupestris  as  a 
stock,  but  from  the  first  importations  of  American  vines  into  France  the 
Rupestris  was  quietly  experimented  with  till  about  1882,  when  its  true 
value  was  noted  by  Professor  Millardet.  It  may  be  said  that  more  forms 
of  the  wild  Rupestris  have  been  found  than  is  the  case  with  any  other 
American  species.  Abroad,  the  inferior  varieties  of  the  Rupestris  speed- 
ily gave  place  to  the  more  vigorous  ones,  for,  as  is  the  case  with  the  Riparia, 
as  well  as  all  stocks,  only  the  most  vigorous  should  be  used.  As  a  general 
rule,  it  may  be  said  that  the  characteristics  of  the  valuable  forms  of  the 
Rupestris  are  very  great  vigor,  strong  trunk  and  canes,  with  thick3  shiny 


RESISTANT   VINES;    THEIR   SELECTION,    ADAPTATION,    ETC.  27 

leaves.  One  should  rigorously  reject  and  destroy  all  varieties  having  pale 
green  or  yellowish,  thin  leaves.  As  is  the  case  with  the  use  of  all 
inferior  varieties,  one  courts  certain  financial  loss  if  such  varieties  are 
tried.  The  selection  of  only  the  very  strongest  growers  is  perhaps  more 
necessary  for  the  Rupestris  than  is  the  case  with  the  Riparia. 

The  Vitis  Rupestris  is  divided  into  two  main  groups,  classed  accord- 
ing to  the  characters  of  the  leaves.  The  first  group  comprises  all  those 
varieties  whose  leaves  are  quite  (comparatively)  small;  their  manner 
of  growth  is  generally  more  bushy  than  those  of  the  other  groups. 

This  first  grand  division  may  be  subdivided  into: 

(1)  Varieties   that  are   very   bushy   growers,   with   very   numerous 
secondary  and  tertiary  ramifications.    The  main  branches  are  relatively 
short.     The  leaves  are  very  much  folded  together,  with  parallel  edges 
almost  touching,  so  situated  as  to  resemble  tiles  on  a  roof.     They  are 
frequently  dull  colored  on  the  superior   surface  and  of   a   yellowish- 
green  on  the  inferior  surface.     These  forms  are  not  vigorous,  and  the 
leaves  are  apt  to  fall,  becoming   honeycombed,  with   small  black  spots 
(melanose) .     As  a  general  rule,  this  form  should  be  rejected. 

(2)  A  group  of  Rupestris  which  embraces  the  most  vigorous  forms, 
with  very  large  trunks,  and  principal  canes  that  are  less  trailing,  but 
with  strong  and  numerous  secondary  ramifications.     The  leaves  of  this 
group  are  of  medium  dimensions  in  ordinary  fertile  soils,  and  are  shiny 
on  each  surface.     Among  the  best  known  varieties  of  this  group  we  may 
mention  the  Rupestris  Mission,  Rupestris  du  Lot,  Rupestris  Ganzin,  etc. 

The  second  grand  'division  comprises  all  the  large-leaved  Rupestris; 
larger  leaved  than  those  of  the  preceding  group  when  grown  on  the 
same  kind  of  soil.  They  are  of  bushy  growth,  and  the  ramifications 
are  less  numerous  than  those  of  the  preceding.  The  leaves,  while  folded 
together,  are  more  open  than  in  the  first  grand  division.  Most  all  of 
the  Rupestris  of  this  group  are  very  vigorous  and  large  wooded,  and 
are  subdivided  into: 

(1)  Large,  thick-leaved  varieties,  with  the  superior  surface  of  a  quite 
deep  green  color  and  wrinkled.     Example:  Rupestris  Metallica,  Violet- 
leaved  Rupestris,  etc. 

(2)  Varieties  with  large,  fleshy,  shiny  leaves,  whose  edges  are  quite 
open,  and  whose  surface  is  sometimes  quite  wrinkled  between  the  prin- 
cipal  and   secondary   nerves.     Example:    Rupestris    Ecole,    Rupestris 
Fort  Worth,  etc. 

(3)  Varieties  that  have  very  large,  fleshy,  almost  flat  leaves,  which 
are  almost  as  wide  as  long.     These  kinds  do  not  grow  as  bushy  as  the 
preceding  groups,  and  would  certainly  seem  to  be  hybrids  of  some  kind 
with  other  species.     They  are  commonly  considered,  however,  as  pure 
Rupestris.     Examples:     Kansas  Rupestris,  Rupestris  No.  62  of  Jaeger's 
catalogue,  etc. 

Prof.  Pierre  Viala,  of  the  Institut  Agronomique  of  France,  from  whose 
lectures  and  most  valuable  book  on  "Adaptation  "  we  have  taken  much 
that  is  valuable  in  this  bulletin,  has  given  the  following  resisting  power 
to  the  better  known  Rupestris  varieties:  (The  maximum  perfection 
is  20.) 

Resistance. 

Rupestris  Mission 18 

Rupestris  du  Lot _ _ _ .  16 

Rupestris  Ganzin 18 

Rupestris  Martin... 18 

The  Violet-Leaved  Rupestris 18 


28  UNIVERSITY    OF    CALIFORNIA. 

Resistance. 

Rupestris  Metallica 16 

Rupestris  Ecole 18 

Rupestris  of  Kansas 18 

Rupestris  of  Fort  Worth,  Texas - 18 

Rupestris  No.  62  of  Jaeger's  Catalogue _. 16 

Rupestris  "Y" 18 

Celeburne  (Texas)  Rupestris 16 

Rupestris  No.  64 18 

Rupestris  No.  65 17 

The  above  are  a  few  of  the  best  known  varieties  of  the  Rupestris;  but 
as  we  have  remarked,  the  mere  resistance  to  the  phylloxera  does  not,  in 
all  cases,  determine  the  true  value  of  the  variety  in  question.  Still,  it 
is  one  of  the  most  important  factors  in  the  problem.  This  point  cannot 
be  brought  out  too  strongly,  for  too  much  money  has  been  absolutely 
lost  from  the  neglect  to  consider  the  resisting  power  of  the  variety  one 
would  employ  in  the  planting  of  a  vineyard,  especially  when  there 
have  been  vines  destroyed  by  the  phylloxera  on  the  same  soil.  With 
resistance  to  the  phylloxera  must  be  taken  into  consideration  the  adap- 
tability of  the  variety  in  question.  These  forms  have  been  chosen  by 
the  University  of  California,  for  introduction  into  California,  from  the 
mass  of  Rupestris  varieties,  as  much  for  their  adaptability  as  for  their 
resistance.  Among  these  some  are  found  that,  though  they  do  not 
possess  as  much  absolute  resistance  as  others,  yet,  on  account  of  their 
easy  adaptability,  they  are  in  many  cases  as  highly  esteemed  as  those 
which  have  a  higher  resisting  power.  It  is  for  this  reason  that  in  selecting 
from  the  one  hundred  and  fifty  and  more  varieties  of  Rupestris  to  intro- 
duce into  California,  the  University  selected  the  Rupestris  St.  Georges. 
Not  that  it  is  very  much  better  than  the  other  good  varieties,  but  as  it  is 
the  object  of  the  University  to  establish  as  a  fact  that  which  is  denied  by 
many  in  California,  namely,  that  there  are  varieties  of  all  the  species 
of  American  vines  some  of  which  are  better  than  others,  and  if  an  inferior 
variety  is  selected  money  will  be  lost.  It  is  confidently  believed  that, 
as  soon  as  the  vine-growers  come  to  a  realization  of  the  fact  that  there 
are  good  and  bad  varieties,  and  that  bad  varieties  mean  loss,  and  the 
good  varieties  mean  profit,  they  will  at  once  attend  to  the  importation 
of  the  other  good  varieties. 

The  Rupestris  St.  Georges  was  selected  from  the  list  just  given  for  the 
reason  that  it  suckers  less  than  the  others,  is  an  erect  grower,  and, 
above  all,  is  a  variety  that  will  grow  in  a  greater  variety  of  soils  and 
climates  than  most  of  the  others.  It  is  within  the  range  of  prob- 
ability that  there  may  be  other  varieties  of  the  Rupestris  that  will 
be,  as  a  whole,  better  suited  to  California  conditions  than  the 
Rupestris  St.  Georges,  but  as  at  the  present  moment  the  Station  is 
trying  to  establish  a  custom  (selection  of  varieties  of  species),  the  most 
vigorous  grower  and  likely  variety  has  been  selected,  proposing,  in  the 
near  future,  to  supply  those  who  wish  to  try  them,  with  other  varieties 
that  may  do  better,  and  will  feel  more  than  satisfied  if  the  present 
varieties  of  resistants  can  but  be  improved  upon,  even  if  the  very  best  has 
not  been  secured.  It  is  very  certain  that  the  Rupestris  St.  Georges  is 
a  more  vigorous  grower  and  thicker  wooded  than  any  of  the  Rupestris 
thus  far  found  in  this  State.  While,  for  various  reasons,  it  is  in  this 
bulletin  called  Rupestris  St.  Georges,  it  must  be  remembered  that  it  has 
many  other  names,  such  as  the  "  Rupestris  Phenomene,"  "  Rupestris  Phe- 
nomene  du  Lot,"  "Rupestris  Sijas,"  "Rupestris  Monticloa,"  "Rupestris 


RESISTANT   VINES;    THEIR   SELECTION,    ADAPTATION,    ETC.  29 

St.  Georges  erige,"  etc.  These  are  synonyms  that  are  fully  recognized 
on  the  market,  so  that  the  same  variety  will  always  be  obtained  under 
any  of  these  names.  The  name  of  "  Rupestris  St.  Georges  "  has  been 
chosen  for  many  reasons,  but  chiefly  in  order  to  avoid  confusion  in  the 
future. 

As  soon  as  the  California  vine-grower  has  been  convinced  that  he  must 
use  only  selected  varieties  in  the  replanting  of  his  vineyard,  full  descrip- 
tions of  the  various  varieties  of  the  Vitis  Rupestris  will  be  given,  so  that 
the  refinements  of  the  problem  may  be  taken  into  consideration. 

As  already  said,  it  is  thought  that  in  the  majority  of  California 
soils  the  Rupestris  will  have  to  be  relied  on  rather  than  the  Riparia, 
as  is  the  case  in  Europe.  Hence  it  has  been  given  the  first  place 
on  the  list,  in  the  belief  that  the  absence  of  summer  rains,  and  the 
abundance  of  light  gravelly  or  sandy  soils,  will  require  in  all  but 
exceptional  cases,  this  hardy,  vigorous  grower.  While  it  does  not  graft 
quite  so  readily  as  the  Riparia,  and  needs  careful  suckering  for  the  first 
few  years,  yet  it  will  do  so  much  better  than  the  Riparia  on  similar  dry 
soils  that  there  can  be  no  question  about  the  gain  in  quantity  and 
quality  of  crops. 

It  must  be  remembered  that  the  native  habitat  of  the  Vitis  Rupestris 
differs  from  that  of  the  Vitis  Riparia,  in  that,  instead  of  seeking  the 
moist,  shady  banks  of  streams  or  the  depths  of  forests,  it  is  found  in 
the  open,  dry  beds  of  ravines,  plunging  its  hardy,  deep  roots  into  soils 
that  are  but  little  better  than  gravel  piles,  without  shelter  of  any  kind. 
In  such  soils  the  Vitis  Riparia  can  scarcely  exist,  and  if  it  does  succeed 
in  struggling  along,  it  is  so  feeble  that  diseases  of  any  kind  will  kill  it. 
The  native  habitat  of  the  Vitis  Rupestris  embraces  soils  that  are  far  more 
arid  and  poor  than  any  of  the  vineyard  land  in  California.  While  it 
flourishes  in  most  excessive  heat  that  would  be  very  harmful  to  other 
species,  it  will  stand  excessive  cold  very  well.  This  was  proved  in 
France  (near  Lyons)  in  the  exceptional  winter  of  1890-91.  And  though 
it  is  said  by  many  that  the  "  experience  of  Frenchmen  should  be  disre- 
garded, because  our  conditions  are  different,"  it  would  seem  common 
sense  that  if  a  certain  variety  of  vine  will  stand  cold  and  be  thick-wooded 
when  transplanted  into  France,  there  is  no  reason  why  it  should  not  be 
thick-wooded  and  stand  the  same  amount  of  cold  in  California  or  any 
other  country  into  which  it  is  carried.  It  has  been  proved  beyond  the 
possibility  of  rational  doubt  that  the  Vitis  Rupestris  does  equally  well 
in  France  as  it  does  in  its  native  habitat  in  the  eastern  part  of  the 
United  States,  provided  the  soils  are  similar.  There  is  no  doubt,  there- 
fore, that  if  it  is  planted  in  similar  soils  in  California,  for  it  is  not  a 
native  of  California,  it  will  thrive  equally  well.  It  is  certain  that  it 
will  not  do  as  well  as  the  Vitis  Riparia  when  planted  in  compact  clay  or 
adobe  soils,  and  if  the  clay  or  adobe  be  in  great  excess,  and  especially 
compact,  even  the  Vitis  Riparia  will  have  to  be  substituted  by  the 
hybrid  Lenoir,  or  Solonis,  or  some  other  similar  hybrid. 

The  Vitis  Rupestris,  then,  is  a  species  that  should  be  selected  for 
all  soils  that  are  gravelly,  sandy,  and  dry.  The  most  important  item  in 
this  list  is  the  drought,  for  while  the  Vitis  Riparia  will  do  well  in  moist 
soils  of  almost  all  kinds,  it  will  not  do  well,  if  at  all,  in  dry  soils,  in 
which  the  Rupestris  will  thrive.  On  moist  soils  the  Rupestris  will 
thrive,  but  other  things  being  equal,  the  Riparia  will  do  better  on  rich, 
moist  land,  especially  if  there  be  much  sand  mixed  with  it. 


30  UNIVERSITY    OF    CALIFORNIA. 

Thus  it  will  be  seen  that  in  selecting  the  species  of  resistant  vines  to 
plant,  more  attention  should  be  given  to  the  physical  condition  of  the 
soil  than  to  the  chemical  composition;  there  is  one  exception,  and  that 
is  in  the  case  of  an  excessive  amount  of  calcareous  material,  in  which 
neither  the  Rupestris  nor  the  Riparia  will  thrive  as  well  as  some  of  the 
other  American  species,  such  as  the  Vitis  Berlandierij  which  though  very 
vigorous,  etc.,  will  not  grow  from  a  cutting. 

Prof.  Viala,  undoubtedly  the  greatest  living  authority  on  viticulture, 
says:  "Among  the  diverse  forms  of  the  Rupestris  we  recommend  the  fol- 
lowing from  a  strictly  practical  point  of  view  as  the  most  valuable  in 
replanting  vineyards:  Rupestris  St.  Georges,  Rupestris  Martin,  Rupestris 
Mission,  and  Rupestris  Ganzin.  These  alone  should  remain  under 
culture.  The  others,  though  possessing  a  certain  undoubted  value,  are 
inferior,  because  they  lack  resistance  or  all-around  adaptability.  The 
Rupestris  Martin,  on  account  of  its  great  resistance  to  the  phylloxera, 
should  always  be  used  in  poor,  silicious,  gravelly  soils,  with  or  without  a 
considerable  amount  of  lime.  The  Rupestris  St.  Georges  replaces  actually 
the  Lenoir  and  Solonis  in  poor  calcareous  soils,  where  formerly  the 
Vialla,  Lenoir,  etc.,  were  used.  The  ungrafted  Rupestris  will  frequently 
show  an  alarming  number  of  black  spots  on  the  leaves,  so  abundant  in 
some  cases  as  to  cause  the  dropping  of  a  few  of  them.  This  is  due  to 
the  melanose,  a  disease  of  the  vine  that  never  does  any  harm  at  all,  and 
should  alarm  no  one.  As  soon  as  the  Rupestris  is  grafted  this  will  dis- 
appear from  the  vineyards,  as  it  can  scarcely  live  on  the  Vitis  Vinifera, 
but  takes  more  kindly  to  the  American  vines." 

VITIS  RIPARIA. 

This  is  undoubtedly  one  of  the  most  valuable  species  of  the  American 
vines  for  the  all-around  reconstitution  of  the  vineyards  of  the  world.  Its 
chief  value  lies  in  its  ready  adaptability  to  a  greater  number  of  soils  than 
almost  any  other  species.  There  are  undoubtedly  others  that  have  a 
greater  resistance  to  the  phylloxera  and  greater  vigor,  but  they  either 
refuse  to  grow  from  cuttings,  or  they  require  soils  of  such  a  special 
nature  that,  when  taken  away  from  their  native  habitat,  they  refuse  to 
thrive. 

In  the  outset  of  the  selection  of  American  resistants  in  1874,  Prof. 
Millardet,  of  the  University  of  Bordeaux,  called  attention  to  the  remark- 
able qualities  of  the  Vitis  Riparia.  Since  then  his  predictions,  as  in 
the  case  of  the  Vitis  Rupestris,  have  been  verified.  There  is  probably 
no  other  American  species  that  is  as  widely  scattered  in  America  on  a 
greater  diversity  of  soils  and  in  all  climates  as  the  Vitis  Riparia.  It 
was  this  that  led  to  its  being  experimented  with  so  carefully.  Its 
greatest  recommendation  is  its  ready  adaptability,  growing  as  it  does  on 
almost  any  kind  of  soil  and  standing  extreme  heat  as  well  as  cold. 
The  Vitis  Cordifolia  and  Vitis  Rotundifolia  are  certainly  more  resistant 
and  more  vigorous  than  the  Riparia,  but  as  they  refuse  to  grow  from 
cuttings  and  require  only  the  most  special  soils  and  climates,  they  of 
course  cannot  be  compared  with  the  Riparia. 

The  one  weak  point  of  the  Riparia  is  its  insistence  on  moisture  and  a 
certain  amount  of  richness  and  fertility  in  the  soil.  It  is  this  that  will 
probably  make  it  less  valuable  for  the  majority  of  California  soils  than 
it  has  proved  itself  to  be  in  Europe.  Undoubtedly,  when  the  Riparia 


RESISTANT    VINES;     THEIR    SELECTION,   ADAPTATION,    ETC.  31 

is  well  suited  to  the  soil  it  is  better  than  any  other  known  resistant, 
and  should  be  preferred  to  either  the  Vitis  Rupestris  or  any  of  the 
hybrids,  such  as  the  Lenoir,  Herbemont,  Solonis,  Doaniana,  Clinton, 
etc.  The  great  problem  is  to  determine  the  nature  of  the  soil,  and  be 
sure  that  there  is  fertility,  depth,  and  moisture  enough  to  suit  the 
Riparia.  The  physical  conditions  and  the  absence  of  much  lime  are 
the  only  special  points  that  should  be  considered  in  the  suitability  of  a 
soil  for  Riparia. 

Thus  far  the  Riparia  has  been  spoken  of  as  a  whole  species,  but  the 
point  must  be  emphasized  that  there  are  varieties  of  Riparia  that  should 
never  be  planted  under  any  circumstances.  All  weak,  thin-wooded  Riparias 
should  be  avoided,  as  the  planting  of  feeble  resistant  stock  means  certain 
loss  of  the  capital  used  in  planting  them — as  well  as  the  subsequent  cul- 
tivation of  the  soil — till  the  fact  becomes  so  apparent  that  the  digging  up 
of  the  vineyard  thus  planted  is  necessitated.  In  this  State  there  are, 
undoubtedly,  all  of  the  varieties  of  the  Riparia  existing  in  the  vineyards, 
but  none  of  them  have  been  classified  or  named,  and  vineyardists  propa- 
gate indiscriminately  from  all  these  varieties  that  are  mixed  up  together. 
This  is  so  true  that  there  are  quite  few  who  really  believe  that  there  are 
such  divisions  as  varieties  of  Riparia.  In  order  to  illustrate  the  fact, 
the  following  groupings  of  type  forms  are  given — not  merely  varieties, 
but  types,  each  type  embracing  many  varieties: 

I.      TOMENTOSE  RlPAKIAS. 

(1)  Large-leaved.    Examples  of  varieties  of  this  sub-group:  Riparia  Scribner, 

Riparia  Giant,  Violet  Riparia,  etc. 

(2)  Small-leaved.    (All  of  these  should  be  rejected  as  worthless.) 

II.    GLABROUS  RIPARIAS. 

(1)  Lobed  leaves.    Example:  Riparia  Palmata,  etc. 

(2)  Entire  leaves.    This  group  is  subdivided  into : 

(A)  Small-leaved  Riparias ; 

(B)  Large-leaved  Riparias,  while  "B  "  is  further  subdivided  into : 

(a)  Dull-colored  leaves  ;  (a')  Thin-leaved  Riparias  ;  (a")  Thick-leaved 
Riparias.  Example:  Riparia  Baron  Perrier,  Riparia  with, 
Bronze  shoots,  Violet-wooded  Riparias,  Riparia  No. 6  and  No.  12 
of  Meissner's  Catalogue,  etc. 

(6)  Shiny,  thick-leaved  Riparias  ;  (6')  Round-leaved  Riparias  (Exam- 
ple :  Riparia  of  Indian  Territory);  (6")  Elongated-leaved 
Riparias  (Example :  Riparia  Gloire  de  Montpellier,  Riparia 
Scupernong,  Riparia  Grande  Glabre,  etc.). 

From  these  groups  of  types  it  will  be  seen  what  a  problem  the  student 
of  American  vines  has  before  him.  Fortunately  for  the  people  of  Cali- 
fornia the  problem  is  almost  completely  solved.  There  is  no  necessity 
to  send  to  the  native  forests  and  get  hundreds  of  thousands  of  cuttings, 
and  experiment  with  them  for  years,  to  find  out  the  groupings  and 
characteristics  of  each  group  and  sub-group.  The  vineyardist  can 
profit  by  the  quarter  of  a  century  of  vast  labor  and  experiment  expended 
on  the  problem  by  those  who  have  made  a  success  of  2,500,000,000  of 
resistants.  All  that  is  to  be  done  is  to  send  to  France  and  ask  for  one 
or  more  of  the  approved  varieties  that  have  certain  definite  and  known 
characteristics,  and  begin  to  experiment-  then  where  the  French  left  off. 
One  can  then  simplify  his  studies  by  having  varieties  before  his  eyes, 
which  are  definitely  named  and  their  qualities  known.  In  spite  of  this 
opportunity  to  profit  by  the  costly  experiments  of  others,  most  of  the 
California  vine-growers  refuse  to  do  so.  They  insist  on  sending  to  the 
forests  and  getting  what  chance  throws  in  their  way.  They  may  get  a 
good  variety  the  first  time,  but  the  truth  is,  that  they  get  a  good  one 


32  UNIVERSITY    OF    CALIFORNIA. 

once  in  ten  thousand  times.  Any  one  who  has  been  in  the  forests  where 
these  vines  grow,  will  find  in  some  cases  two  or  more  distinct  species 
climbing  on  the  same  tree.  Now  these  species  hybridize  naturally,  and 
the  seedlings  that  grow  around  are  mere  nondescripts,  neither  Riparias 
nor  Rupestris.  As  the  cuttings  are  gathered  when  the  leaves  have 
fallen,  even  the  chance  of  getting  the  correct  species  is  problematical. 

It  is  very  simple  to  get  a  few  tried  varieties  and  plant  them  near  a 
stream  or  in  a  garden  where  they  can  be  forced  to  go  to  wood,  and  in  a 
very  short  time  plant  out  a  large  vineyard  with  something  that  is  defi- 
nitely known.  This  is  what  the  foreign  vine-growers  do,  and  they  have 
eliminated  a  great  many  uncertainties  from  the  problem.  In  California 
there  is,  under  the  present  regime,  nothing  certain  to  serve  as  a  guide. 
The  soils  must  be  studied  and  their  general  characteristics  determined, 
as  the  Europeans  have  done.  This  is  quite  simple,  but  vine-growers 
plant,  they  know  not  what,  and  if  that  fails,  do  not  try  something 
that  has  certain  well-defined  characteristics,  but  go  on  blindly  planting 
vines  of  whose  characteristics  they  are  in  perfect  ignorance. 

It  is  the  object  of  the  University  to  establish  the  fact  that  the  vine- 
grower  can  reduce  the  chances  of  failure  and  loss  of  money  to  a  minimum 
as  soon  as  he  will  plant  only  good  varieties.  To  make  a  beginning,  it 
has  attempted  at  first  not  to  confuse  the  minds  of  those  who  would 
study  the  problem  by  the  introduction  of  a  number  of  varieties.  They 
will  come  later.  At  the  present  time  the  Station  has  introduced,  reim- 
portedj  three  of  the  best  known  and  most  generally  planted  varieties  of 
Riparia,  feeling  confident  that  once  the  vine-grower  has  seen  the  selected 
Riparia  planted  by  the  side  of  the  nondescript  from  Nebraska,  he  will 
abandon  the  present  system  of  trusting  to  kind  Providence  to  do  every- 
thing for  him,  and  will  help  himself.  There  are  to-day,  in  this  State, 
examples  of  the  selected  Riparias  growing  alongside  of  the  nondescripts, 
under  exactly  similar  conditions,  and  those  who  doubt  should  go  to  see 
them.  The  most  striking  example  is  to  be  found  on  the  place  of  John 
Swett  &  Son,  near  Martinez,  in  Contra  Costa  County. 

The  varieties  of  Riparia  that  the  University  have  imported  are 
Riparia  Gloire  de  Montpellier,  Riparia  Grande  Glabre,  and  Riparia 
Martin.  These  were  chosen  for  their  great  resistance  to  the  phylloxera, 
and  especially  for  their  characteristic  of  being  easily  suited  in  a  very 
great  variety  of  soils.  Below  is  given  a  table  in  which  the  comparative 
value  of  these  will  in  part  be  shown.  In  the  scale  adopted,  20  is  taken 
as  the  highest  possible  number  df  points  in  the  determination  of  its  value: 

Resistance.  Vigor. 

Riparia  Scribner  ._ _. 18  20 

Riparia  Gloire  de  Montpellier _. 18  20 

Riparia  Grande  Glabre 18  20 

Riparia  Martin _. _ 18  20 

Riparia  Scupernong  _  ^ _ 18  17 

Riparia  Baron  Perrier . 18  16 

Giant  Toinentose _ _.  18  19 

This  table  was  made  out  from  a  comparison  of  the  various  varieties  of 
Riparia  growing  under  favorable  circumstances.  It  is  probable  that 
under  more  unfavorable  conditions  the  vigor  of  the  Grande  Glabre  and 
the  Gloire  de  Montpellier  would  be  increased. 

One  advantage  the  Riparia  has  over  the  Rupestris  is  that  it  is  more 
easily  grafted  when  old  than  the  Rupestris.  In  this  State,  where  vine- 
yardists  still  insist  on  planting  the  cuttings  in  place  instead  of  in 


RESISTANT   VINES;    THEIR    SELECTION,    ADAPTATION,   ETC.  33 

nursery,  they  are  more  apt  to  get  better  results  from  grafting  old  Ripa- 
rias.  It  is  hoped  that  the  day  is  not  far  distant  when  a  cutting  will 
never  be  planted  in  place,  but  that  there  will  be  varieties  which  give 
such  large  canes  that  the  cutting  can  be  grafted  and  planted  in  the 
nursery;  and  when  it  has  rooted,  joint  can  be  examined,  imperfectly 
grafted  vines  rejected,  and  only  uniformly  perfect  vines  planted.  In 
this  way  a  paying  crop  will  be  gotten  two  years  sooner  than  under 
the  present  system.  I  know  full  well  that  there  are  very  distinguished 
men  in  the  State  who  say  that  they  have  tried  it  and  failed,  and  hence 
conclude  that  everybody  else  will  fail.  The  fact  remains  that  there  are 
tens  of  thousands  of  vine-growers  the  world  over  who  have  tried  it  and 
have  made  a  success  of  it;  so  much  so  that  they  practice  no  other  system. 
Attention  is  called  to  the  fact  that  in  those  countries  where  cutting- 
grafting  is  now  successful,  when  it  was  first  suggested,  there  were  many 
who  said  that  "they  had  tried  it  and  failed,"  but  others  tried  it  and  now 
all  of  the  vine-growers  use  this  system  and  no  other. 

The  point  intended  to  be  emphasized  is  that  nurseries  for  vines  and 
cutting-grafting  are  no  longer  unestablished  theories,  but  solid  facts. 
It  is  perfectly  true  that,  for  a  slipshod  farmer,  the  old  system  of  place 
planting  and  grafting  presents  fewer  difficulties,  but  for  one  who  would 
get  the  maximum  from  his  capital,  and  that  as  soon  as  Nature  allows, 
the  cutting-graft  is  the  better.  There  are  many  things  that  have  to  be 
taken  into  account.  Cuttings  must  not  be  allowed  to  dry  out,  nor  must 
they  be  drowned  with  irrigation;  nor  must  the  scions  be  cut  one  day 
and  exposed  to  the  wind  and  sun  for  twenty-four  hours,  as  I  have  seen 
it  done.  The  cuttings  as  soon  as  cut,  should  be  grafted  and  put  care- 
fully away  in  moist  sand  and  not  be  exposed  to  the  inclemencies  of  the 
weather.  Finally,  the  nursery  must  be  properly  cultivated  and  closely 
watched,  and  not  trusted  to  the  tender  mercies  of  a  Chinaman  who 
knows  nothing  about  what  he  is  caring  for.  If  one  will  give  the  proper 
attention  to  these  details  he  will  find  that  cutting-grafting  and  nursery- 
ing  pays,  but,  if  he  cannot  give  all  of  these  attentions  to  the  cutting,  he  had 
far  better  continue  in  the  good  old  way,  planting  cuttings  in  place,  leav- 
ing them  three  or  more  years,  and  then  grafting. 

The  following  letter  is  interesting  in  connection  with  Riparias;  but 
the  same  differences  between  selected  and  non-selected  vines  occur  with 
all  the  American  species.  The  letter  is  self-explanatory: 

HILL  GIRT  VINEYARD,  JOHN  SWETT  &  SON,  { 

MARTINEZ,  CONTRA  COSTA  COUNTY,  CAL.,  December  20, 1896.  f 

A.  P.  HAYNE,  ESQ.,  Berkeley,  Gal.: 

DEAR  SIR:  The  question  of  the  adaptation  to  particular  soils,  of  different  varieties  of 
resistant  vines,  I  consider  to  be  a  matter  of  the  first  importance.  I  have  planted  a  large 
number  of  various  varieties  of  resistants,  and  intend  to  keep  careful  records  of  their 
growth  and  adaptation  to  our  soil  and  climate  here  in  the  Amambra  Valley.  I  have 
found  such  a  great  difference  in  the  growth  of  the  various  varieties  of  Riparia,  that  I 
want  to  call  your  attention  to  results.  I  have  found,  in  talking  with  many  grape- 
growers,  both  in  this  county  and  elsewhere,  that  the  impression  seems  to  prevail  that 
there  is  only  one  variety  of  Riparia,  and  that  it  is  all  nonsense  to  talk  about  different 
varieties  of  the  species.  I  would  like  to  have  some  of  the  so-called  "practical  people" 
who  talk  this  way  examine  the  different  Riparias  we  have  growing  here. 

For  instance,  "I  have  growing,  side  by  side  in  nursery,  several  thousand  each  of 
Riparias,  imported  last  spring  from  Nebraska  by  the  Viticultural  Commission,  and 
others  obtained  from  vineyards  near  Judge  Stanley's  place  in  Napa,  and  said  to  be  of 
the  same  stock  as  his  vines.  Both  sorts  were  planted  at  the  same  time,  in  the  same 
manner,  and  by  the  same  laborers.  The  soil  is  uniform  throughout  the  patch— a  yellow, 
sandy  wash  soil,  fairly  retentive  of  moisture. 

When  the  vines  started  out  in  the  spring,  the  Nebraska  Riparia  seemed  slightly 
stockier  and  stronger  growing.  The  leaves  were  slightly  larger,  and  in  the  month  of 
3— RV 


34  UNIVERSITY   OF    CALIFORNIA. 

July,  though  the  canes  were  not  quite  as  long  as  the  canes  on  the  Napa  Riparia,  I  think 
tha^t  the  growth  of  wood  was  of  about  equal  weight.  But  in  August,  the  difference  in 
"adaptation"  began  to  show.  When  the  long,  hot,  dry  days  came  on,  although  the 
ground  was  still  moist  and  in  good  condition,  the  Nebraska  vines  stopped  growing. 
They  did  not  get  scorched,  nor  sunburned,  nor  sick,  but  they  simply  remained  station- 
ary. Their  season  of  growth  came  to  a  sudden  end.  I  do  not  doubt  that  frequent  irri- 
gation would  have  kept  them  growing,  but  as  we  do  not  propose  to  plant  a  vineyard  that 
will  require  irrigation,  we  thought  it  best  to  let  them  alone. 

On  the  other  hand,  the  Napa  Riparia  kept  on  steadily  growing  until  the  frost  came. 
I  have  measured  the  growth  of  wood  on  adjoining  rows  of  the  two  kinds  of  vines,  and 
I  give  you  some  of  the  figures  to  show  how  they  run : 

Length  of  Canes. 

Nebraska  Riparia.  Napa  Riparia. 

(Unselected  variety.)  (Practically  selected  varieties.) 

10  inches.  34  inches. 

11  inches.  44  inches. 
20  inches.  40  inches. 
13  inches.  48  inches. 

18  inches.  24  inches. 
24  inches.  61  inches. 
13  inches.  52  inches. 

19  inches.  72  inches. 

20  inches.  51  inches. 
36  inches.  72  inches. 
24  inches.  44  inches. 
28  inches.  12  inches. 

Average  growth :  20  inches.  Average  growth :  46  inches. 

*"-  These  figures  are  fairly  taken,  and  the  vines  have  grown  in  about  the  same  ratio  all 
over  the  patch.  Now  I  have  come  to  the  conclusion  that  the  selected  Riparia  is  worth 
much  more  on  our  soil  here  than  those  that  came  fresh  from  the  woods,  doubtless  from 
the  bank  of  some  stream  where  the  roots  got  all  the  water  they  required.  I  believe  a 
large  number  of  these  were  planted  down  near  Livermore,  and  it  may  be  that  on  that 
soil  they  have  done  better  than  here.  If  you  can  hear  of  any  one  down  there  that  has 
faith  in  the  vines  of  this  importation,  on  whose  soil  these  vines  have  made  gO9d,  thrifty, 
strong  growth,  I  wish  you  would  let  me  know,  for  I  will  sell  the  2,000  rooted  vines  I  have 
on  hand  very  cheap  indeed.  I  do  not  wish  to  say  that  they  are  not  good,  but  "  there  are 
others,"  and  they  are  so  much  better  that  we  are  going  to  use  these  others  for  our 


The  Riparia  Grande  Glabre  and  Glorie  de  Montpellier  made  a  still  heavier  growth  than 
the  two  sorts  I  have  compared,  but  as  they  were  grown  in  other  soil  and  under  different 
conditions  a  comparison  would  not  be  strictly  fair.  Next  year  I  shall  have  the  Napa 
Riparia  and  the  "  Montpellier"  growing  side  by  side,  so  that  I  can  form  a  better  opinion 
as  to  their  relative  merits  than  I  have  now.  Grafted  on  old  vines,  the  *'  Montpellier " 
made  a  growth  of  21  feet  of  cane  where  an  unselected  Riparia  made  a  growth  of  8  feet 
and  very  spindly  and  poor  at  that. 

??  I  send  you  by  express  typical  vines  of  "Nebraska"  Riparia  and  of  the  "Napa,"  to 
illustrate  their  relative  growth.  You  will  notice  near  to  root  of  the  "  Nebraska  "  vine 
a  long  swelling.  This  was  caused  by  a  borer  with  which  these  vines  were  infested  when 
they  arrived.  ^1  think,  though,  that  the  disinfecting  solution  used  on  the  cuttings  must 
have  killed  them  all  last  year,  for  I  have  been  unable  to  find  any  of  the  borers  on  the 
vines  this  year. 

Very  truly  yours, 

FRANK  F.  SWETT. 

LENOIR;  HERBEMONT. 

Lenoir— Resistance  to  phylloxera,  12.    Herbemont— Resistance  to  phylloxera,  13. 

Owingjto  the  interest  in  this  State  in  these  two  hybrids — especially  the 
former — and  the  quite  extensive  plantings  already  made,  as  well  as  those 
contemplated,  a  somewhat  fuller  account  of  them  is  given  than  we 
otherwise  would. 

The  best  ampelographers  hold  that  the  Lenoir  and  the  Herbemont  are 
hybrids  of  three  species:  the  resistant  species  ^Estivalis,  the  resistant 
Cinerea,  and  the  non-resistant  species  Vinifera.  The  characteristics  of 
the  Vinifera  are  less  pronounced  in  the  case  of  the  Lenoir  than  in  the 
case  of  the  Herbemont,  or  the  Cunningham,  which  belongs  to  the  same 
group. 

The  origin  of  these  vines  is  very  uncertain,  and  much  of  historical 


RESISTANT   VINES;    THEIR    SELECTION,    ADAPTATION,    ETC.  35 

interest  has  been  written  on  the  subject.  Mr.  T.  V.  Munson,  the  sava*nt 
nurseryman,  of  Denison,  Texas,  places  them  in  a  separate  group,  which 
is  nothing  more  nor  less  than  the  old  "  Southern  ^Estivalis  "  group  of 
Engelmann.  This  Mr.  Munson  dignifies  with  the  place  of  a  separate 
species  under  the  name  of  Vitis  Bourquiniana,  in  honor  of  G.  Bourquin, 
of  Savannah,  Ga.,  who  has  done  good  work  in  studying  them. 

Without  wishing  to  enter  into  the  controversy,  I  will  follow  the  ideas 
of  the  best  ampelographers,  such  as  Millardet,  Viala,  Foe'x,  etc.,  and 
regard  them  as  hybrids,  as  I  think  there  is  ample  proof  of  this  position. 

The  Lenoir  and  Herbemont  have  a  great  affinity  for  the  Vitis  Vinifera 
in  grafting,  which  explains  the  fact  that  the  production  and  maturity  of 
the  grafted  Lenoir  and  Herbemont  are  in  no  way  hastened  or  increased, 
as  is  the  case  when  the  Vinifera  is  grafted  on  the  Rupestris  or  Riparia. 

Neither  of  these  hybrids  grow  as  readily  from  cuttings,  nor  do  they 
graft  with  the  same  facility,  as  the  Riparia  or  Rupestris.  It  is  a  mis- 
take, however,  to  suppose  that  they  are  very  poor  indeed  in  this  respect, 
as  some  say.  There  is,  however,  a  marked  difference  in  the  percentage 
of  cuttings  and  grafts  that  take,  and  the  difference  shows  the  superiority 
of  the  Rupestris  and  Riparia. 

Both  of  these  hybrids  stand  cold  very  well.  Their  resistance  (12)  is 
not  great,  but  is  sufficient  in  good  soil  in  cold  countries.  In  warm 
countries  they  become,  in  many  cases,  so  affected  by  the  attacks  of  the 
phylloxera  that  they  either  succumb,  or  become  so  feeble  that  after 
some  years  they  do  not  yield  paying  crops.  In  warm  climates,  then, 
these  two  hybrids  must  have  a  rich,  fertile,  cool  soil,  or  they  will  not 
pay.  There  are  cases  in  some  of  the  warmer  parts  of  the  vineyards  of 
the  world  where  these  have  been  grafted  for  twenty-six  years,  and  are 
still  thrifty;  but  in  every  case  the  soil  was  especially  rich,  deep,  and  cool. 

It  has  been  established,  after  a  quarter  of  a  century  of  experiment  with 
these  two  hybrids,  that  they  do  not  pay  as  stocks,  except  in  some 
slightly  compact  calcareous  soils,  such  as  will  not  grow  either  Rupestris 
or  Riparia.  The  Herbemont  is  especially  valueless,  either  as  a  stock  or 
a  direct  producer.  The  Lenoir  is  more  valuable,  especially  on  compact, 
cold  blue  clays,  or  adobes.  As  a  direct  producer  the  Lenoir  is  an 
undoubted  failure.  Owing  to  its  vigor  on  rich  land  and  its  deep- 
growing  roots  it  has  in  this  State  been  found  to  do  better  on  dry 
land  than  the  nondescript  Riparias.  This  is  not  surprising,  for  a  feeble 
resistant  is  worthless  anyway,  and  a  feeble  Riparia  on  dry  soil  is  utterly 
valueless. 

If  used  as  a  stock,  the  grafts  that  take  the  best  and  thrive  are  those 
that  are  made  on  vines  that  are  several  years  old — six,  seven,  and 
more.  This  is  the  reverse  with  the  Riparia  and  Rupestris. 

The  hybrids  of  Vitis  Labrusca  and  Vitis  Riparia  furnish  us  with  two 
that  have  played  an  important  part  in  the  replanting  of  the  vineyards 
of  the  world.  These  are  the  Clinton  and  Vialla.  The  Clinton  has  now 
been  abandoned,  except  in  very  special  cases  not  necessary  to  dwell  upon ; 
while  the  Vialla  is  still  used  in  certain  of  the  eastern,  cold,  granitic 
regions  of  central  France.  In  hot,  and  especially  in  dry  countries,  it 
rapidly  succumbs  to  the  attacks  of  phylloxera.  Hence  it  possesses  but 
little  interest  for  California. 


36  UNIVERSITY   OF    CALIFORNIA. 

SOLONIS. 
Resistance  to  phylloxera,  14. 

This  is  a  hybrid  of  the  Vitis  Candicans,  Vitis  Riparia,  and  Vitis 
Rupestris. 

Mr.  T.  V.  Munson  has  made  a  special  species  of  a  group  of  which 
Solonis  is  a  type.  He  calls  it  Vitis  Novo  Mexicana;  but  there  is  little 
doubt  that  it  is  a  hybrid. 

Though  this  vine  has  but  moderate  resistance,  it  is  especially  valuable 
for  cold,  compact  soils  that  are  too  moist  for  any  other  American  vine 
except  the  Lenoir.  Its  special  value  for  California  is  its  quality  of 
growing  well  in  salty  or  alkali  lands  where  no  other  resistant  would  live. 
In  dry  or  poor  soils  it  will  perish  from  the  phylloxera. 

DOANIANA. 

This  is  also  a  hybrid  of  the  same  species  as  the  Solonis,  but  Mr.  Mun- 
son has  classed  it  as  a  species — calling  it  Vitis  Doaniana.  There  is  no 
doubt  at  all  but  that  it  is  a  hybrid.  There  are  several  forms  of  it,  as 
is  the  case  with  every  group  of  hybrids.  Some  interest  has  been  created 
in  this  State  concerning  it,  and  two  of  the  best  forms  have  been  pro- 
cured from  Mr.  Munson's  valuable  nursery  in  Texas.  The  two  forms 
thus  far  imported  are  the  late  and  early  Doaniana.  It  is  valueless  as  a 
direct  producer,  having  far  too  many  of  the  characteristics  of  the  Mus- 
tang. As  a  stock,  it  is  vastly  inferior  to  the  Solonis,  and  has  been 
abandoned  in  other  countries. 

VITIS    CALIFORNICA. 

This  species  is  found  in  all  parts  of  California,  extending  partly  into 
Oregon  and  Arizona.  It  is  one  of  the  most  beautiful  of  all  the  Ameri- 
can vines.  There  are  numberless  forms  of  this  species,  differing  widely 
in  their  characteristics  and  habits.  Mr.  Munson  has  formed  two  species 
out  of  what  the  other  ampelographers  call  the  Vitis  Calif ornica — namely, 
the  Vitis  Calif  ornica,  found  in  the  northern  part  of  the  State,  growing 
only  on  the  rich,  moist  banks  of  streams,  and  the  Vitis  Girdiana,  found 
chiefly  in  the  southern  part  of  the  State,  growing  in  the  dry,  sandy  soils 
of  that  region.  This  making  of  two  distinct  species  I  think  is  a  mis- 
take, and  I  shall  regard  them  as  two  groups  of  one  species. 

Many  suppose  that  because  all  the  other  American  vines  resist 
the  phylloxera  almost  equally  well,  this  is  the  case  with  the  Vitis 
Californica.  This  is  an  error.  The  flora  of  California  differ  sensi- 
bly from  that  of  the  eastern  part  of  the  United  States;  and  the  wild 
grapevine  of  this  State,  while  having  preserved  a  little  of  the  resist- 
ing qualities  of  the  Eastern  species,  evidently  came  out  here  in  ages 
when  the  full  resistance  to  the  phylloxera  was  not  wholly  developed. 
Certain  it  is  that  the  resistance  to  the  phylloxera  is  very  low,  but  little 
better  than  that  of  the  Vitis  Vinifera,  being  but  4  out  of  a  possible  20. 
It  grows  so  vigorously  in  its  native  habitat  that  many  suppose  that  its 
resistance  is  much  greater  than  it  really  is.  In  judging  of  the  resistance 
of  a  vine,  however,  one  must  not  be  governed  by  its  growth  or  vigor,  but 
by  the  nature  of  the  cancerous  spots  caused  by  the  phylloxera  on  its 
roots.  As  has  been  shown,  a  vine  may  possess  a  very  feeble  resistance 
to  phylloxera,  and  yet  maintain  its  vigor  for  some  time  by  reason  of  its 


RESISTANT   VINES;    THEIR   SELECTION,    ADAPTATION,    ETC.  37 

special  adaptation  to  the  soil  and  climate.  This  is  the  case  with  the 
Californica.  There  is  but  little  doubt  that  along  the  rich,  moist  creek- 
beds  of  its  native  home  it  may  be  able  to  withstand  the  phylloxera  for 
an  indefinite  time;  but  it  is  very  certain  that  once  it  is  removed  to  drier 
or  different  and  more  unfavorable  conditions,  it  will  speedily  perish  from 
the  attacks  of  the  insect.  This  has  been  the  case  wherever  it  has 
been  tried  under  unfavorable  conditions.  It  grafts  readily  and  grows 
well  from  cuttings,  and  is  most  vigorous.  Undoubtedly,  if  the  Califor- 
nica is  to  be  depended  upon,  vigorous  specimens  from  the  wild  vines 
growing  in  dry  places  should  be  looked  for,  as  dryness  is  one  of  the  chief 
characteristics  of  our  soils. 

In  selecting  cuttings  for  planting,  the  vineyardist  should  carefully 
study  the  nature  of  the  special  soil  of  the  vineyard,  and  try  to  select 
wild  vines  growing  on  as  nearly  similar  soils  as  possible. 

As  is  the  case  with  all  the  other  American  species,  there  are  hundreds 
of  varieties  of  the  Vitis  Californica,  and  most  of  them  will  be  found  to 
be  worthless.  So,  in  selecting,  look  for  vigor,  thickness  of  cane,  and  resist- 
ance to  drought.  The  Californica  should  evidently  not  be  used  as.  a  stock 
when  good  Riparia  or  Rupestris  can  be  obtained. 

VITIS   ARIZONICA. 

This  is  a  species  that  inhabits  Arizona  and  New  Mexico.  It  possesses 
quite  a  good  resisting  power — 16  out  of  a  possible  20;  grows  readily  from 
cuttings,  and  grafts  well.  It  has  not  been  well  tried  in  California,  but 
time  may  show  that  a  readily  adaptable  stock  can  be  obtained  from  it. 
It  is  certain  that  it  is  inferior  as  a  stock  to  the  Riparia  and  Rupestris, 
and  where  even  the  Arizonica  will  grow,  the  Riparia  or  Rupestris  will 
do  well;  so  that  for  the  present,  experimentation  with  it  should  be  limited. 


GRAFTING. 

The  grafting  of  the  vine  is  an  operation  that  has  come  down  to  us 
from  the  earliest  times.  In  fact,  to-day  our  processes  differ  but  little 
from  those  described  so  minutely  by  the  Romans.  It  is  especially  since 
American  vines  came  into  use  as  stocks  that  resist  the  phylloxera,  that 
the  grafting  of  the  grapevine  has  become  common.  Formerly  it  was 
used  merely  as  a  rapid  way  of  changing  the  varieties  in  a  vineyard; 
while  to-day,  on  the  contrary,  all  vines  must  be  grafted,  either  before 
planting,  or  after  the  vineyard  has  been  planted  out. 

It  was  in  1869  that  Messrs.  Laliman  and  Gaston  Basile  called  atten- 
tion to  the  importance  of  this  operation  in  the  reconstitution  of  the 
phylloxera-ravaged  vineyards  of  the  Old  World.  To-day  it  is  an  opera- 
tion which  each  and  every  vine-grower  is  forced  to  practice.  In  Cali- 
fornia but  little  attention  has  been  paid  to  this  most  important  operation; 
and  if  one  will  but  take  the  trouble  to  examine  some  of  the  grafted 
vineyards  of  the  State,  he  will  find  some  specimens  of  the  poorest 
handiwork  imaginable.  In  fact,  some  of  the  reported  failures  of  the 
grafted  vineyards  are  traceable  to  this  cause.  To  those  who  are  expert 
grafters  (and  there  are  many  such),  my  excuses  for  dwelling  somewhat 
at  length  on  this  subject  are  offered  in  advance.  I  do  so,  however,  in 
order  to  answer  many  questions  from  many  who  are  not  experts,  but 
who  have  the  desire  to  be. 


38  UNIVERSITY    OF    CALIFORNIA. 

ANATOMY    AND    PHYSIOLOGY    OF    THE    GRAFT. 

(a)  The  Tissue  of  the  Joint. — On  the  lower  section  of  a  graft  pruned 
to  one  or  two  eyes/and  placed  in  appropriate  conditions  as  to  heat  and 
moisture,  there  will  appear  small  protuberances  of  tissue,  called  callus, 
on  the  inner  edges  or  lips  of  the  cut  or  section.  (Just  as  at  the  base  of 
all  cuttings.  See  Fig.  1.)  These  protuberances  are  but  gatherings  of 
cicatricial  tissue.  They  are  all  the  more  numerous  and  developed  as 
they  are  nearer  the  base  of  the  section;  and  on  an  obliquely-cut  graft  or 
scion  (as  is  cut  for  an  "  English  graft,"  see  Figs.  2,  3,  and  4),  it  is  at  the 
lower  extremity  of  the  wedge  that  they  first  appear.  They  are  destined 
to  cover  the  wound  made  by  the  section,  and  to  shelter  it  from  exterior  influ- 
ences, such  as  those  resulting  from  rots,  etc.,  by  an  envelope  of  cork  with 
which  the  living  parts  of  the  cane  (the  generating  layer,  liber,  bark, 
etc.)  are  covered.  The  juxtaposition  of  a  corresponding  section  (that  of 
the  subject  or  stock)  alters  the  destination  of  the  callus.  The  wood  itself 
has  no  influence  whatever  in  the  formation  of  the  cicatricial  tissue;  it  re- 
mains just  the  same  as  it  was  at  the  moment  of  grafting.  Hence  the  better 
joints  are  made  without  too  great  an  amount  of  wood  being  inclosed;  the 
wood  being  useful  only  for  stiffness.  Too  much  or  too  little  wood  is 
equally  bad.  A  certain  amount  is  necessary  to  give  bark  enough  to 
form  callus.  The  principal  part  in  the  formation  of  the  callus  devolves 
on  the  cambium  or  generating  layer.  The  mechanism  of  this  forma- 
tion is  somewhat  as  follows:  The  cells  of  the  scion  that  are  in  immediate 
contact  at  the  surface  of  the  section,  and  which  belong  to  the  regions 
constituting  the  generating  layer  or  inner  bark,  become  more  active;, 
they  subdivide,  multiply,  and  become  prolonged  in  a  direction  perpen- 
dicular (or  nearly  so)  to  the  surface  of  the  cut.  The  cells  of  the  soft 
bast  become  transformed  into  still  softer  cells,  the  walls  of  which  are 
thin  and  non-lignified;  they  keep  on  subdividing  and  multiplying,  and, 
united  to  those  that  are  the  tissues  of  those  resulting  from  the  activity 
of>  the  cambium  layer,  they  constitute  the  small  bumps  of  the  cicatricial 
tissue.  Soon  the  exterior  cells,  that  is  to  say  the  oldest,  become  suberi- 
fied  (or  changed  into  cork),  and  in  one  or  two  layers  they  form  the  pro- 
tecting envelope  of  cork,  more  or  less  resistant,  which  incloses  completely 
each  protuberance,  and  which  becomes  attached,  sometimes,  to  the  cork 
envelope  of  the  cane.  On  the  superior  section  of  the  canes  the  same 
phenomena  occur,  but  they  seem  to  be  less  distinct  and  take  place  much 
later  than  is  the  case  with  those  on  the  graft  itself.  This  is  because  the 
cane  (as  is  the  case  with  the  entire  vine)  has  no  tendency  whatever  to 
cover  or  protect  the  wounds  made  on  its  superior  extremities.  The 
terminal  section  of  the  cane  never  covers  itself  with  callus.  The  surface 
of  the  cut  dries  out  to  a  varying  distance,  its  channels  become  clogged 
with  gum,  etc.,  but  never  close  up  with  living  tissue.  Every  one  has 
noticed  that  cuttings  stratified  in  cool  sand  or  soil  form  callus,  especially 
at  the  lower  end  of  the  cane,  and  only  in  most  exceptional  cases  is  any 
callus  found  on  the  upper  end  of  the  cane,  and  even  then  this  is  because 
of  the  juxtaposition  of  another  section  of  cane. 

If  a  longitudinal  section  on  a  cane  is  made,  the  cicatricial  tissue 
forms  at  first  on  the  lateral  edges,  and  scarcely  at  all  on  the  transverse 
section.  Finally,  the  cicatricial  tissue  forms  in  greater  abundance  near 
an  eye  or  bud  than  near  the  middle  of  the  internode.  It  is  the  pro- 
tuberances of  the  cicatricial  tissue  on  the  graft  and  stock  placed  in  con- 


RESISTANT   VINES;    THEIR   SELECTION,    ADAPTATION,    ETC.  39 

tact  with  one  another,  that  form  the  joint.  The  younger  they  are  at  the 
moment  they  join  (that  is  to  say,  the  less  their  cells  are  suberified),  the 
better  will  be  the  joint.  It  will  be  seen  from  this  that  the  various 
regions  of  the  bark  should  be  placed  as  close  together  as  possible.  The 
cells  which  are  derived  directly  from  the  activity  of  the  generating  layer 
become  joined;  one  of  their  layers  is  transformed,  and  becomes  generat- 
ing tissue,  and  unites  with  the  generating  tissue  of  the  stock.  From 
this  moment  the  grafted  stock  grows  normally  till  the  joint  is  com- 
pleted from  the  top  to  the  bottom  of  the  wound,  and  performs  its  functions 
as  though  no  wound  had  been  made,  and  forms  wood  on  the  inside  and 
bast  on  the  outside. 

If  the  bumps  of  callus  be  put  in  contact  when  they  are  old,  the  joint 
is  far  less  perfect,  and  although  a  joint  will  form,  it  will  be  a  very  poor 
one.  The  tissues  are  derived  from  the  activity  of  the  new  generating 
layer,  and  differentiate  so  as  to  continue  either  the  libroligneous  bundles 
or  the  medular  rays,  etc.,  corresponding  to  the  graft  and  the  stock. 
There  will,  however,  be  numerous  anastomoses  formed,  thus  enabling 
the  circulation  to  take  place  almost  as  though  there  had  been  no  inter- 
ruption made  in  the  tissue  made  by  the  graft. 

Such  is  very  roughly  the  mechanism  of  the  joining  of  the  graft  with 
the  stock.  From  the  foregoing  we  have  supposed  that  the  subject  or 
stock  was  a  shoot  or  part  of  a  branch  more  or  less  aged.  One  could, 
however,  have  equally  well  taken  a  root  or  portion  of  one  as  the  stock. 
The  large  roots  of  the  vine  have  (save  a  few  bands  of  bast  fibers) 
sensibly  the  same  structure  as  the  cane  from  one  to  three  years  of  age. 
In  such  a  case  the  joint  is  produced  in  the  same  manner  as  above 
described. 

The  cicatricial  tissue  does  not  form  equally  well  with  all  varieties  of 
the  vine,  whether  used  as  a  graft  or  as  the  stock.  This  is  observed  in  the 
case  of  a  large  number  of  other  plants.  Some  will  scarcely  form  a 
callus  at  all,  while  others  form  it  with  the  greatest  facility.  In  the  case 
of  the  vine,  the  divers  varieties  have  this  peculiarity  in  a  very  marked 
degree.  Thus  we  note  abundant  callus,  hence  easy  grafting,  in  the  case 
of  the  Berlandieri  (which,  however,  will  not  grow  from  cutting),  the 
Vitis  Cinerea,  Rupestris  St.  Georges,  Vialla,  Cabernet  Sauvignon;  and  a 
very  poor  grafting  power  in  the  case  of  the  Solonis,  Folle  Blanche,  etc. 

But  independently  of  the  nature  of  each  variety,  the  formation  of 
tissue  is  profoundly  modified  by  other  exterior  agencies.  According 
to  Prof.  Millardet,  callus  is  most  rapidly  formed  at  a  temperature  of 
68°  F.  Some,  however,  maintain  that  a  temperature  from  87°  to  95°  F. 
is  more  favorable,  but  beyond  this  the  graft  will  suffer.  Below  60°  F. 
the  formation  of  callus  is  very  slow  indeed.  What  is  essential  is  that 
the  temperature  should  be  sufficiently  great,  but  always  regular.  The 
greatest  amount  of  callus  is  found  in  the  case  of  grafts  buried  in  light, 
warm  soils  at  a  depth  sufficient  to  cause  the  variations  of  heat  to  be  as 
light  as  may  be. 

The  degree  of  humidity  of  the  soil  exerts  a  very  great  influence  on 
the  successful  joining  of  the  graft  to  the  stock.  If  a  cutting  or  a  grafted 
cane  be  plunged  into  water  so  as  to  cover  the  lower  parts  of  the  cane, 
no  cicatricial  tissue  whatever  will  form.^  Grafts  covered  with  fine  sand, 
kept  constantly  wet  by  irrigation,  may  put  out  young  shoots,  but  will 
never  form  a  joint.  This  is  frequently  noted  in  the  case  of  stratified 


40  UNIVERSITY    OF   CALIFORNIA. 

grafts  where  too  much  watering  has  been  indulged  in.     In  sand  that  is 
kept  slightly  moist,  on  the  contrary,  the  best  results  are  found. 

On  the  other  hand,  aeration  assists  greatly  in  the  formation  of  callus. 
Growing  cells  respire  more  than  is  ordinary  for  older  ones,  and  hence 
they  require  a  medium  that  is  especially  well  supplied  with  oxygen. 
We  note,  therefore,  that  grafts  that  are  deeply  buried  in  very  compact 
soils  will  scarcely  callus  at  all. 

(b)  Effects  of  Grafting;  Affinity. — It  is  a  general  rule  that  there  is 
an  enfeeblement  of  the  graft,  except  in  the  case  where  the  graft  and  the 
stock  are  of  the  same  variety;  and  it  is  also  a  fact  that  this  is  accom- 
panied with  an  excessive  fructification  of  the  grafted  vine,  especially 
where  the  enfeeblement  is  most  marked.  Together  with  the  excessive 
fructification  is  noted  a  production  of  a  greater  number  of  bunches  which 
are  larger  than  the  normal;  also,  larger  and  better  nourished  berries  of 
earlier  maturity  and  a  greater  richness  in  sugar. 

Another  important  item  in  this  case  is  the  fact  that  there  is  always 
less  "  coulure."  On  the  other  hand,  with  the  enfeeblement  of  the  vine 
by  grafting,  while  the  crop  is  benefited,  there  is  noted  an  increased 
susceptibility  to  the  phylloxera,  as  well  as  swellings  of  more  or  less  size 
at  the  joint  of  the  graft  with  the  stock.  The  effects  of  the  graft  are 
similar  to  that  of  the  annular  incision  so  much  practiced  in  hothouse 
grape  culture  to  give  size  and  sweetness  to  the  grape.  At  the  same 
time,  while  the  results  are  similar,  there  is  quite  a  difference  in  the 
causes.  Beyond  a  mere  interruption  of  sap  in  the  case  of  the  annular 
incision,  the  similarity  ceases.  In  the  one  case  it  is  a  temporary  wound, 
causing  an  interruption  of  the  reflux  of  the  sap;  while  in  the  other  there 
is  a  lack  of  harmony  in  the  functions  of  the  various  parts  of  the  plant, 
which  brings  about  the  same  effect  as  the  annular  incision. 

There  is  a  difference  in  vigor  only  when  the  variety  of  the  graft  and 
of  the  stock  differ,  otherwise  it  is  but  a  wound  that  will  rapidly  heal  up 
and  leave  the  vine  as  it  was  before.  The  greater  the  difference  in 
variety,  the  greater  will  be  the  difference  in  effects.  A  graft  of  the  Vitis 
Vinifera  on  the  group  of  the  American  species  called  Muscadina,  may 
grow  for  a  time,  but  the  graft  is  so  badly  nourished  that  it  soon  perishes. 
The  same  is  true  in  the  case  of  grafts  on  the  Ampelopsis,  Cissus,  etc. 
On  the  Vitis  Riparia,  the  physiological  functions  of  which  are  quite 
different  from  those  of  the  Vitis  Vinifera,  the  difference  in  vigor  is  quite 
marked.  They  are  less  in  the  cases  of  the  other  resistant  stocks  which 
approach  more  closely  the  Viniferas.  In  the  case  of  the  Franco-Amer- 
ican hybrids  these  differences  are  still  less. 

The  chemical  composition  of  the  Franco- American  hybrids  is  the  same 
in  the  case  of  grafted  vines  and  non-grafted  ones,  which  furnishes  us 
with  an  indirect  proof  of  the  greater  affinity  of  the  Franco- American 
hybrid  for  the  Vitis  Vinifera  than  in  the  case  of  the  American  stocks, 
which  do  show  a  chemical  difference  in  composition  between  the  grafted 
and  the  non-grafted  vines,  as  well  as  greatly  diminished  vigor.  Allow- 
ance being  made  for  resistance  to  the  phylloxera,  it  will  be  seen  that  there 
is  greater  affinity  between  the  Franco- American  hybrids  than  between 
the  pure  species.  But  it  is  to  be  noted  that  the  various  European  vari- 
eties do  not  always  behave  alike  on  the  same  stock.  The  Cinsaut  does 
badly  on  the  Riparia,  while  the  Carignan  does  better  than  the  Aramon  on 
theLenoir  and  Riparia.  The  Clairette  is  one  of  the  varieties  of  the  Vitis 


UNIVERSITY 

OF 


RESIST  A  Ny^JEgp^R   SELECTION,    ADAPTATION,    ETC.  41 

Vinifera  that  suffers  the  least  from  grafting.  The  Alicante  Bouschet,  like 
the  Alicante,  from  which  it  is  derived,  grows  old  and  feeble  very  rapidly, 
while  the  Petit  Bouschet  is  much  superior  to  it  in  this  respect.  The 
Grenache  has  but  a  medium  affinity  for  the  resistant  stocks.  The  Ter- 
rets  (Terret  noir,  Terret  gris,  Terret  bouschet)  are  not  very  vigorous 
when  grafted.  The  Morrastel  suffers  but  little,  and  the  Ugni  blanc,  or 
St.  Emillion,  is  quite  vigorous  on  non-calcareous  soils,  where  it  is 
exceedingly  liable  to  chlorose  when  grafted,  as  is  also  the  case  with  the 
Folle  blanche.  Muscats  behave  very  well  after  grafting,  as  do  the 
Picquepoules,  Colombeau,  etc.  The  Cabernet  Sauvignon  maintains  its 
original  vigor,  as  does  the  Cabernet  Franc,  Charmenere,  Verdot, 
and  St.  Macaire.  The  Malbec  is  more  sensitive  to  the  chlorose  after 
grafting  than  are  the  Cabernets,  while  the  Merlot  suffers  but  little. 
The  Sauvignon  and  Muscadelle  do  well  on  resistant  stock,  while  the 
Semillon  leaves  much  to  be  desired.  The  Pinots  are  more  sensitive  to 
the  chlorose  on  dry  or  calcareous  soils  than  are  the  Gamays.  The 
Gamay  noir,  ungrafted,  is  not  a  vigorous  vine,  and  grafted  it  will  never 
be  sufficiently  vigorous;  the  white  Gamay  is  more  satisfactory  hi  this 
respect.  The  same  may  be  said  of  the  Ploussard.  The  Syrah  takes  on 
great  development  when  grafted,  and  may  be  said  to  be  one  of  the 
JEuropean  varieties  that  does  exceptionally  well  on  resistant  stocks.  The 
same  may  be  said  of  the  Mondeuse,  if  we  except  cases  where  the  subsoil 
is  exceedingly  calcareous.  The  Etraire,  Persan,  Durif,  Corbeau,  and 
Roussanne  do  well  grafted,  while  the  Marsanne  is  less  vigorous. 

SYSTEMS   OF   GRAFTING. 

It  will  not  be  possible  in  this  brief  discussion  to  describe  all  the 
various  systems  of  grafting,  as  practiced  in  all  parts  of  the  world.  It 
will  be  merely  an  attempt  to  give  the  essential  points  of  the  two  most 
usual  and  most  simple  and  practical  that  are  in  use  in  the  majority  of 
cases  with  practical  vine-growers. 

English  Graft.  —  In  practicing  the  sections  for  this  graft,  the  stock  and 
scion  should  be  cut  in  the  same  manner  (Figs.  2,  3,  and  4).  They  should 
have  the  same  surface  and  the  same  contour,  and,  therefore,  be  of  the  same 
size.  The  stock,  be  it  a  rooted  vine  or  a  cutting,  is  cut  sloping  (or  beveled) 
at  an  angle  of  from  14  to  17  degrees  with  the  axis  of  the  cane  or  trunk. 
The  cut  is  made  as  near  the  eye  as  is  possible;  for,  as  we  have  shown,  it 
is  at  this  point  that  tissues  which  form  the  joint  develop  with  the  greatest 
rapidity.  The  length  of  the  cut  is  proportional  to  the  diameter  of  the 
cane  or  trunk.  At  an  angle  of  from  14  to  17  degrees  it  is  generally 
sufficiently  long  to  afford  firmness  and  stability. 

Grafts  and  stocks  are  generally  cut  by  hand,  though  there  are  many 
"  grafting  machines  "  in  use.  I  think  that  the  experience  of  the  world 
has  been  that,  in  the  end,  it  is  economy  to  have  the  cutting  done  by 
hand;  though  at  first  a  clumsy  workman  may  do  better  with  a  "machine." 
But  none  but  clever  hands  should  ever  be  allowed  to  attempt  to  graft, 
and  then  they  should  have  a  certain  time  allowed  them  to  "  get  their 
hands  in."  Experience  has  shown  that  it  requires  an  ordinary  work- 
man as  much  time  to  learn  how  to  properly  use  a  "  grafting  machine  " 
as  it  does  a  good,  intelligent  man  to  learn  to  hand-cut  all  the  grafts 
and  master  the  technique;  while  there  is  room  for  constant  improve- 


42  UNIVERSITY    OF    CALIFORNIA. 

»i> 

ment,  which  is  impossible  in  the  case  of  machine  grafting.  The  sections 
should  be  made  with  a  single  stroke  of  the  knife,  which  must  be  very 
sharp,  otherwise  there  will  be  so  many  irregularities  that  a  good  joint, 
depending  as  it  does  on  close  contact,  will  be  impossible.  The  slanting 
section  being  made  with  one  clean  cut  of  the  knife,  another  cut  is  made, 
parallel  with  the  fibers  of  the  wood  of  the  cane  and  stock  (Fig.  4),  to  a 
depth  of  at  least  one  fourth  of  an  inch.  In  withdrawing  the  blade  of  the 
knife,  care  should  be  taken  to  give  it  a  slight  rotary  motion  so  as  to 
press  the  lips  of  the  cut  apart,  and  thus  facilitate  the  insertion  of  the 
corresponding  tongue  of  the  other  part  to  be  joined. 

The  object  of  this  parallel  cut  is  twofold:  to  insure  firmness  in  holding 
the  two  parts  together  until  the  callus  has  formed  and  new  wood  devel- 
oped at  the  joint;  but  most  especially  is  it  for  the  purpose  of  increasing 
the  surface  where  callus  can  form  and  thus  enhance  the  chances  of 
getting  a  good  joint.  The  exact  position  of  the  parallel  cuts  is  of  little 
importance,  and  should  not  be  too  seriously  considered.  So  far  as  regards 
the  life  of  the  cane,  the  pith  is  of  no  importance  at  all,  and,  hence, 
can  bfc  disregarded  in  the  consideration  of  the  problem.  Of  so  little 
importance  is  the  pith  that  it  can  be  removed  without  injury  to  the 
cane. 

The  only  importance  of  the  position  of  the  parallel  cuts  rests  in  the 
fact  that  the  beginning  and  the  end  of  the  cut  must  be  at  equal  dis- 
tances from  the  center  of  the  cane,  in  order  that  the  cuts  in  the  graft  and 
the  stock  can  be  in  exact  juxtaposition.  It  will  be  seen  from  this,  that 
the  nearer  the  cuts  are  made  to  the  center  of  the  section,  the  shallower  they 
should  be,  and  also  the  farther  they  are  from  the  center,  the  deeper  they 
should  be.  If  these  directions  be  not  carefully  followed  the  adjusting  of 
the  corresponding  parts  of  the  graft  and  stock  will  be  defective;  the  two 
short  sections  will  not  be  able  to  cover  each  other,  and  the  excessively 
long  sections  will  be  lacking  in  solidity.  The  graft  or  scion,  whether 
it  be  of  one  or  two  eyes,  is  cut  exactly  as  is  the  case  with  the  stock.  The 
accompanying  figures  are  given  to  illustrate  these  points  (Figs.  2  and  4). 

The  English  graft,  or  whip  graft,  is  one  that  gives  the  best  joints;  the 
scion  and  the  stock  being  cut  so  as  to  correspond  exactly,  gives  greater 
surface  for  the  formation  of  callus,  which  forms  on  all  parts  of  the  cut 
surface  of  the  bark  so  well  that  the  healing  takes  place  on  all  parts  of 
the  wound.  This  causes  the  sap  to  circulate  almost  as  though  there  had 
been  no  interruption  whatever.  On  the  other  hand,  while  this  system 
gives  by  far  the  best  joints,  it  gives,  perhaps,  fewer  cases  of  success  with 
the  unskillful  workman;  but  if  well  done  the  difference  is  so  slight,  com- 
paratively, as  to  make  it  the  favorite  system  of  all  those  who  have 
carefully  experimented  with  it.  It  is  to-day  the  most  common  in  all 
the  large  vineyards,  and  especially  in  the  nurseries  of  France,  where 
grafting  has  been  so  extensively  and  thoroughly  tested. 

Perhaps  one  of  the  reasons  why  this  system  is  not  highly  esteemed  in 
this  State  is  because  of  the  difficulty  of  getting  cuttings  of  resistant 
vines  that  are  large  enough  to  be  grafted  before  planting.  Owing  to 
the  very  poor  varieties  of  the  resistant  vines  that  have  thus  far  prevailed 
here,  together  with  the  method  of  planting  the  cuttings  in  place  and 
waiting  several  years  before  they  were  large  enough  to  be  grafted,  this 
system  has  not  been  given  a  fair  trial.  With  the  importation  of  varieties 
of  resistants  which  give  canes  fully  as  large  as  any  of  the  Viniferas, 
things  will  change,  and  it  will  be  found,  as  has  been  the  case  elsewhere, 


KESISTANT   VINES;    THEIR    SELECTION,    ADAPTATION,    ETC.  43 

"that  "  English "  grafting  is  the  best  of  them  all.  By  grafting  the 
cuttings,  and  then  planting  the  grafted  cutting  in  nursery,  much  of  the 
expense  connected  with  the  planting  of  a  vineyard  on  resistant  roots 
will  be  obviated.  It  would  certainly  seem  that  if  a  people  who  have 
made  a  success  of  2,500,000,000  grafts  have  adopted  this  system  as  their 
favorite,  it  is  worth  our  consideration. 

Cleft  Graft. — In  this  case  the  stock  is  always  larger  than  the  graft,  or 
scion,  the  section  being  generally  made  with  a  shears  or  saw,  as  the  size 
of  the  trunk  warrants.  This  is  the  most  common  system  in  California 
where  but  little  nursery  grafting  is  practiced;  partly  from  the  necessities 
of  the  case,  arising  from  the  fact  that  it  has  been  deemed  necessary  to 
graft  only  older  vines,  partly  from  the  fact  that  our  resistant  stock  is  of 
such  poor  and  feeble  varieties  that  it  is  difficult  to  obtain  scions  that 
are  anywhere  near  the  same  size  as  the  stock.  This  difficulty  being 
about  to  become  a  thing  of  the  past,  vineyardists  may  look  forward  to 
the  time  when  the  cleft  graft  will  be  practiced  only  in  special  cases,  and 
"  English"  grafted  cuttings  will  be  planted  in  nursery. 

The  accompanying  figures  are  given  to  illustrate  what  is  meant  by 
cleft  grafting  (Figs.  1  to  9).  This  system  having  been  so  well  described 
and  so  generally  known  in  this  State,  it  is  not  necessary  to  dwell  on 
details,  remarking  in  passing  that  with  the  illustrations  and  the  general 
principles  already  given,  even  a  novice  can  readily  learn  it  rapidly. 

It  is  to  be  observed  from  the  general  principles  set  forth  in  the 
preceding  part  of  the  discussion  that  there  should  be  as  complete  a 
juxtaposition  of  the  generating  layers  of  the  two  barks  as  may  be. 
Also,  that  while  moisture,  if  in  excess,  is  bad  for  grafts  in  the  process  of 
"  taking,"  on  the  other  hand,  too  great  dryness  is,  if  possible,  worse.  It 
is  probable  that  in  California  more  damage  is  done  from  drought  than 
from  excessive  wetness  at  the  graft.  I  have  seen  many  grafters  cut  the 
stock,  as  well  as  the  scions,  and  leave  them  exposed  to  the  action  of  the 
sun  and  wind  for  many  hours  before  covering  them  or  joining  them 
together.  Not  only  this,  but  in  a  naturally  dry  soil  they  either  cover 
the  graft  too  little,  or  cover  it  with  perfectly  dry,  hot  earth.  As  has 
already  been  said,  air  is  necessary  to  the  formation  of  callus,  but  so  is 
moisture,  neither  being  in  excess.  This  means  that  the  grafts  must  be 
covered  not  only  with  loose,  but  moist  (not  wet)  soil.  It  is  because  of 
this  that  compact  wet  or  dry  adobes  or  clays  are  found  to  be  very  bad 
for  successful  grafting  in  nurseries,  partly  on  account  of  lack  of  aera- 
tion, partly  on  account  of  the  natural  tendency  of  such  soils  to  "  pack  " 
and  "bake,"  and  partly  on  account  of  the  almost  impossibility  of 
retaining  sufficient  moisture  in  them.  Hence  it  is  that  for  nurseries  we 
should  always  select  a  very  sandy,  moist  soil,  in  default  of  which  it  will 
be  found  that  it  will  pay  to  haul  sand  to  put  around  the  joint  of  the 
graft  and  the  stock.  This  is  frequently  done  with  the  greatest  benefit. 
Moderate  irrigation  is  advisable  in  almost  all  the  soils  of  California 
when  they  are  used  for  nurseries.  As  a  general  rule,  the  drier  and  more 
refractory  the  soil,  the  deeper  should  be  the  burying  of  the  graft,  it  being 
understood  that  the  graft  should  be  ordinarily  about  an  inch  below  the 
natural  level  of  the  land.  In  cases  where  there  is  a  great  excess  of 
vigor  of  the  scion  over  the  stock,  the  depth  of  the  graft  should  be 
greater,  though  deep  grafting  necessitates  the  annual  cutting  away  of 
the  suckers  from  the  graft  above  the  stock. 


FIG.  4. 


FIG.  7. 


FIG.  8. 


FIG.  9. 


Fig.  1.    Formation  of  callus  on  a  scion  cut  for  a  cleft-graft. 
Fig.  2.    Stock  and  scion  ready  for  whip-graft  for  cuttings  and  small  vines. 
Fig.  3.    Manner  of  cutting  scion. 

Fig.  4.    Respective  positions  of  parallel  cuts  in  scion  and  stock  of  cleft-graft. 
Figs.  5  and  6.    Ordinary  cleft-graft  on  old  vine ;  the  dotted  lines  showing  the  manner 
of  banking  the  grafted  vine  in  ordinary  moist  soils. 
Fig.  7.    The  scion  cut  for  cleft-graft. 
Fig.  8.     Manner  of  using  raffia  on  a  cutting  whip-graft. 
Fig.  9.    Manner  of  using  raffia  when  lead  strips  are  used. 


RESISTANT   VINES;    THEIR    SELECTION,    ADAPTATION,    ETC.  45 

Ligatures. — In  the  case  of  crown  or  cleft  grafts  (on  vines  of  more 
than  one  year,  selected  varieties)  ligatures  are  seldom  necessary.  The 
only  object  of  binding  the  graft  to  the  stock  is  to  give  solidity,  which  is 
furnished  by  the  natural  stiffness  of  a  large  stock — such  are  usually 
cleft-grafted.  In  the  case  of  grafting  a  vine  with  a  thick  trunk,  the 
scion  will  be  held  in  place  naturally.  The  practice  of  daubing  clay 
or  mud  around  a  graft  cannot  be  too  strongly  condemned,  for  it  pre- 
vents respiration — which  has  been  shown  to  be  especially  necessary  for 
the  formation  of  callus — and  it  furnishes  no  solidity  whatever. 

The  smaller  the  diameter  of  the  stock  the  more  the  necessity  of  liga- 
tures becomes,  for  there  is  not  sufficient  natural  stiffness  to  maintain 
the  scion  in  place. 

The  use  of  cotton  "grafting  twine"  (such  as  is  commonly  used  in 
nurseries  for  grafting  trees  and  shrubs — above  ground)  has  been 
abandoned  by  those  who  have  tried  it  on  grafted  vines.  The  reason  is 
that  it  has  no  elasticity,  and  will  not  decay  in  time  to  permit  the  free 
development  of  the  stock,  but  has  to  be  cut  off  about  June  or  July. 

The  use  of  patent  elastic  bands  has  also  been  abandoned,  because  of 
too  great  expense;  although  they  are  excellent  in  aiding  good  joining. 

At  one  time  split  corks  bound  with  wire  were  highly  thought  of  and 
used  to  a  considerable  extent;  but  owing  to  the  expense  of  the  raw 
material,  as  well  as  the  necessity  for  removing  them  in  July  or  August, 
they  were  abandoned.  As  in  the  case  of  the  rubber  bands,  they  accom- 
plish the  object  most  perfectly,  but  are  too  expensive. 

The  best  and  cheapest  material  now  used  is  raffia,  which  serves  the 
purpose  of  holding  the  two  parts  of  the  graft  together,  and  while  it  is 
cheap,  it  seldom  requires  cutting  off,  as  in  ordinary  moist  soils  it  will 
rot  off.  When  first  used  it  is  very  strong,  and  will  stand  all  the  strain 
necessary  to  bind  the  two  parts  of  the  graft  firmly  together.  Owing  to 
the  rapidity  with  which  it  will  rot  in  very  moist,  warm  soils,  and  the 
danger  of  resulting  infection  of  the  joint  with  the  micro-organisms  of 
decay,  it  is  frequently  dipped  in  a  solution  of  from  1  to  3  grams  of 
sulphate  of  copper  to  the  quart  of  water.  While  this  certainly  accom- 
plishes its  object  of  preventing  infection,  it  very  materially  retards  the 
process  of  callusing.  This  is  obviated,  in  part,  by  washing  the  dipped 
or  soaked  raffia  in  running  water,  which  removes  the  copper  sulphate 
or  bluestone.  When  "  bluestoned "  raffia  is  used,  some  nurseries  use 
tin  or  lead  strips,  around  which  they  tie  the  ligature  of  raffia.  This  is 
too  expensive  an  operation,  however,  for  very  general  use,  aside  from 
the  bad  effects  of  the  tin  or  lead  salts  that  form  and  hinder  the  forma- 
tion of  callus. 

Almost  every  grafter  has  his  own  favorite  method  of  tying  the  knot. 
This  is  immaterial,  so  long  as  the  raffia  is  not  too  loosely  or  closely 
wound  on — so  as  not  to  afford  support  or  to  touch  and  suffocate.  Too 
close  winding  prevents  free  access  of  air,  which  has  been  shown  to  be 
necessary  for  the  proper  formation  of  callus. 

We  give  an  illustration  of  how  raffia  is  usually  tied,  in  Fig.  8  and 
Fig.  9. 

Time  for  Grafting. — Grafting  can  be  done  at  almost  any  time  between 
February  and  May,  according  to  the  season.  Some  prefer  late,  while 
others  hold  to  early  grafting.  I  think  that  the  most  experienced  and 
successful  grafters  prefer  the  earlier  method.  The  danger  from  late 


46  UNIVERSITY    OF    CALIFORNIA. 

grafting  is  that  the  soil  covering  the  grafted  vine  or  cutting  will  dry  out, 
in  which  case  failure  is  assured,  while  too  early  grafting  will  incur  the 
risk  of  rotting.  Some  suppose  that  the  scion  is  "drowned,"  if  grafting 
is  done  when  the  sap  is  beginning  to  flow  so  that  the  vine  "  bleeds." 
This  is  an  error;  perhaps  some  of  the  most  successful  grafts  are  made 
early.  While  there  is  little  to  be  feared  from  the  excess  of  sap  in  the 
vine  at  grafting,  there  is  much  to  fear  from  rains  at  this  time.  It  is 
certainly  better  to  take  chances  from  moisture  rather  than  from 
drought — either  extreme  being  bad  for  the  success  of  the  operation. 

It  is  on  account  of  danger  arising  from  excess  of  drought  or  moisture 
that  special  care  should  be  given  to  the  "banking"  or  covering  of  the 
grafted  vine  or  cutting.  Covering  too  deeply  is  almost  as  bad  as 
insufficient  covering.  In  very  moist  soils  and  climates  especial  care 
should  be  given  not  to  bury^  too  deeply — while  when  there  is  a-ny  ten- 
dency to  dry  out,  deep  burying  is  to  be  advised.  There  is  a  limit,  of 
course,  even  in  the  driest  of  climates;  if  a  graft  be  too  deeply  buried, 
the  shoots  or  growth  experience  very  great  difficulty  in  forcing  their 
way  to  the  air  and  making  proper  growth.  It  is  for  this  reason  that 
scions  of  two  buds  are  preferable  to  those  of  one.  In  the  former  case 
the  top  bud  can  grow  freely,  and  it  is  seldom  that  the  second  eye,  the 
nearest  stock,  will  develop  at  all.  In  very  dry,  loose  soils -it  is  well,  per- 
haps, to  use  even  three  eyes  or  buds. 

Cutting  Off  of  Roots. — It  is  necessary  about  July  or  August,  according 
to  locality,  to  carefully  cut  away  the  roots  that  may  have  started  on 
the  scion.  By  this  time  the  joint  is  pretty  well  formed.  The  roots  that 
grow  on  the  scion  are  not,  after  all,  any  very  great  obstacle  to  the 
"  taking"  of  the  graft,  and  if  their  development  is,  as  is  well  known, 
inverse  to  the  production  of  callus,  they  are  in  most  cases  the  conse- 
quence of  a  slow  joining.  Their  suppression  in  July  or  August  is  too 
late  to  materially  affect  the  joining  of  the  scion  to  the  stock,  but  they 
must  be  none  the  less  carefully  removed.  This  is  because  when  the 
scion  is  partly  nourished  by  its  own  roots,  and  partly  by  those  of  the 
stock,  neither  the  one  nor  the  other  plays  its  proper  part  in  the  vegeta- 
tion of  the  plant;  and  as  the  non-resistant  scion  is  partly  interrupted 
in  its  communication  with  the  roots  of  the  stock,  it  tends  to  draw  more 
freely  from  its  own  roots,  with  which  it  has  uninterrupted  communica- 
tion, than  from  the  stock.  The  result  is  that  most  all  the  root  develop- 
ment takes  place  on  the  non-resistant  roots  and  the  resistant  stock 
becomes  unduly  enfeebled,  so  that  when  the  phylloxera  attacks  the  roots 
of  the  scion,  the  resistant  roots  are  unable  to  nourish  the  large  develop- 
ment of  foliage.  This,  deprived  of  its  nourishment,  becomes  sickly,  and 
in  many  cases  causes  the  whole  vine  to  perish.  Of  course  all  suckers 
should  be  removed  as  soon  as  they  make  their  appearance. 

Care  to  be  Given  the  Grafted  Vines. — In  very  cold  regions,  where  there 
is  damage  from  extreme  cold  in  winter,  the  grafted  vines  should  be 
"  banked  up  "  at  the  beginning  of  winter,  and  early  in  spring  the  soil 
should  be  plowed  away  from  them. 

The  stock  is  frequently  more  feeble  than  the  scion,  especially  on 
the  Riparia  and  Solonis;  and  hence  is  exposed  to  the  danger  of  break- 
ing off  from  wind,  etc.  The  rupture  seldom  takes  place  just  at  the  joint 
itself,  but  generally  (in  the  case  of  a  well-grafted  vine)  just  a  little  below 
the  joint.  It  is  well,  then,  to  "  stake"  the  grafts  for  a  few  years. 


RESISTANT   VINES;    THEIR    SELECTION,    ADAPTATION,    ETC.  47 

Pinching  back,  as  is  sometimes  deemed  necessary,  is  a  useless  opera- 
tion, though  it  is  a  harmless  one. 

Great  care  should  be  taken  to  sulphur  well  the  young  growth  on  the 
grafted  vine  against  oidium  (powdery  mildew),  and  treat  with  Bordeaux 
mixture  against  peronospora  (downy  mildew)  and  black  rot. 

Sometimes  rooted  vines  from  the  nursery  are  planted  in  autumn,  to  be 
grafted  the  following  spring,  or  in  May.  In  this  case  there  is  really  a 
better  chance  of  successful  grafting  than  in  the  case  the  cutting  has 
been  planted  an  entire  year  or  more  previously — that  is,  if  the  rooted 
vine  is  in  healthy  condition. 

Choice  and  Preservation  of  Scions. — In  choosing  the  scions,  one  should 
be  very  careful  to  take  canes  only  from  the  most  vigorous  and  fruitful 
vines  in  the  vineyard.  It  pays,  and  pays  well,  to  go  over  the  vineyard, 
just  before  the  vintage,  and  mark  with  paint  or  a  cloth  the  vines  that 
are  especially  heavy  bearers,  and  take  scions  from  these  only.  Careful 
experiments  on  this  subject  have  been  made  for  a  great  many  years, 
and  it  has  been  established  beyond  dispute  that,  either  for  cuttings  or 
grafts,  it  is  more  profitable  to  select  the  cuttings  or  grafts  from  those  vines 
that  possess  in  the  greatest  degree  the  qualities  desired  in  the  vineyard  that 
one  is  planting. 

Scions  for  early  grafting  (February)  can  be  taken  directly  from  the 
vines,  while  those  for  later  grafting  should  be  cut  off  before  the  first 
movement  of  the  sap,  and  carefully  preserved  in  a  cold  room,  exposed 
to  the  north,  and  they  should  be  buried  in  almost  dry  sand.  They 
should  be  completely  covered  with  sand.  For,  as  has  been  said,  the  stock 
calluses  slowly,  and  it  is  essential  that  it  be  further  advanced  than 
the  scion. 

CUTTING   GRAFTING. 

Canes  of  the  American  resistants  destined  to  be  "  cutting  grafted  " 
should  be  i  inch  in  diameter  at  the  "  small  end."  They  are  cut  10  to 
11  inches  in  length.  The  lower  section  is  made  below,  and  as  near  as 
possible  to  the  eye  (Fig.  2).  This  is  on  account  of  the  facility  with 
which  roots  form  near  the  eyes.  The  upper  section  is  made  1  to  1-J 
inches  above  the  upper  eye.  It  is  well  known  that  the  most  numerous, 
as  well  as  the  most  vigorous,  roots  grow  from  the  eye  itself,  rather  than 
nearer  the  middle  of  the  internode.  This  is  especially  necessary  for  all 
vines  that  grow  with  difficulty  from  cuttings. 

One  can  use  the  entire  cane  of  an  American  resistant  vine  as  a 
"cutting  stock,"  with  the  sole  proviso  that  it  has  a  sufficiently  great 
diameter  to  enable  it  to  hold  the  scion  in  place.  Theoretically  it  can 
be  done  with  almost  any  sized  cane,  but  practically  it  has  been  found 
that  about  i  inch  is  the  least  diameter  of  a  "stock  cutting"  (unless 
in  the  hands  of  a  most  experienced  grafter).  With  selected  varieties, 
especially  if  these  have  been  grown  for  some  years  on  rich,  moist  land, 
or  grafted  on  old,  vigorous  stocks,  the  canes  are  almost  sufficiently  large. 

Here  it  might  be  well  to  note  that  those  who  are  in  haste  to  "  get 
wood  "  from  a  few  cuttings,  should  cut  the  cuttings  into  short  scions  and 
at  once  graft  on  some  vigorous  vine  (resistant  or  non-resistant,  it  makes 
no  difference),  and  they  can  get  abundant  wood  the  same  year.  One 
cannot  depend  on  getting  scions  or  cuttings,  large  enough  for  "  cutting 
grafts,"  from  any  resistant  the  first  year,  if  planted  out  in  place  or  in 
nursery.  This  was  well  illustrated  in  1896  at  the  place  of  John  Swett, 


48  UNIVERSITY   OF    CALIFORNIA. 

of  Martinez,  Contra  Costa  County.  The  University  imported  a  number 
of  selected  resistants,  and  asked  Mr.  Swett  to  make  some  comparative 
experiments  with  the  selected  re-imported  resistants  and  some  non- 
descript varieties  of  the  same  species  he  had  from  a  Nebraska  importation. 
He  grafted  the  two  kinds  side  by  side  on  the  same  variety  of  vine  of  the 
same  age,  and  found  that  while  the  selected  varieties  gave,  in  one  hundred 
and  twenty  days,  twenty-one  foot  canes  over  \  inch  in  diameter,  the  other 
gave  about  one  fourth  the  growth  and  size.  The  balance  of  the  cuttings 
were  planted  at  various  points  in  the  State,  and  few  of  the  canes  were 
large  enough  for  cutting  grafting;  though,  of  course,  they  were  large 
enough  (though  there  were  few  of  them)  for  use  as  cuttings  used  in  the 
old-fashioned  way.  Hence,  to  all  those  who  desire  to  propagate  improved 
varieties,  in  order  to  get  what  cuttings  they  can  the  first  year,  we  would 
recommend  that  they  graft  these  cuttings  on  old,  vigorous  vines.  It 
might  be  well  also  to  advise  here,  that  much  more  available  wood  can 
be  made  if  care  is  taken,  during  the  early  growth  of  the  vine,  to  pinch 
off  all  secondary  growth,  and  confine  the  energies  of  the  vine  to  forcing 
the  main  canes.  This  is  easily  and  cheaply  done,  and  pays  handsomely 
on  the  few  hours'  time  expended  in  this  work.  After  the  first  pressing 
needs  in  supplying  cuttings  have  been  satisfied,  a  few  can  be  planted  on 
some  rich,  moist  land,  and  these  can  be  kept  for  all  time  for  propagating 
purposes.  Vines  thus  preserved  are  called  "  mother-vines." 

Many  suppose  that  it  is  necessary  to  scrape,  or  slash,  the  bark  of  a 
grapevine  in  order  to  facilitate  the  throwing-out  of  roots.  This  is  only 
partly  true.  It  is  never  necessary,  but  in  the  case  of  certain  vines  that 
root  with  difficulty,  such  as  the  Lenoir,  Herbemont,  Solonis,  etc.,  it  may 
do  some  good,  in  facilitating  the  penetration  of  water  into  the  tissue  of 
the  cane,  to  replace  that  which  has  been  lost  by  evaporation  from  that 
part  above  ground.  In  the  case  of  cuttings  that  have  been  slightly 
dried  out,  this  scarring  or  scratching  is  sometimes  profitable. 

The  most  important  thing  in  the  preparation  of  a  "cutting-stock"  is 
the  removal  of  all  the  buds  or  eyes  from  the  stock,  even  the  one  at  the 
very  base  of  the  cane.  It  will  not  suffice  to  pinch  these  off  with  the 
finger-nail.  They  should  be  carefully  cut  away  with  a  knife,  so  that 
they  cannot  possibly  grow  out  again.  Mere  pinching  off  of  the  bud 
causes  four  or  five  others  to  grow  out  around  the  one  suppressed.  These 
live  at  the  expense  of  the  whole  vine,  and  greatly  hinder  the  formation 
of  a  proper  joint. 

This  precaution  is  especially  necessary  in  the  case  of  the  Rupestris. 
This  species  is  accused  of  "taking"  very  poorly  from  cutting-grafts. 
It  would  seem,  however,  that  the  reported  failures  in  this  case  are  due 
solely  to  the  fact  that  the  buds  were  improperly  suppressed. 

In  the  case  of  the  Vialla  or  Riparia  one  can  merely  pinch  them  off; 
but  in  the  case  of  the  Rupestris,  etc.,  they  must  be  cut  off  with  a  very 
small  portion  of  the  bark,  leaving  a  clearly-cut  shield-shaped  cut.  If 
Rupestris  cutting-stocks  are  thus  cut  they  "take"  better  than  almost 
any  other.  Hence,  we  may  advise  that  in  all  cases  of  cutting  grafting, 
the  buds  of  the  stock  should  be  carefully  removed.  Prof.  Viala  tells  us 
of  45,000  grafted  Rupestris  cuttings  that  he  planted,  and  made  80% 
grow  well. 

Mr.  H.  Lefranc,  of  San  Jose,  last  year  imported  a  number  of  grafted 
cuttings  of  Rupeptris  from  France,  and  made  70%  grow,  and  these  had 
been  treated  in  the  same  way. 


NON-SELECTED.  SELECTED. 

Photograph  of  non-selected  and  selected  vines  of  the  same  age  growing  side  by  side  in 
the  vineyard  of  John  Swett  &  Son,  Martinez,  Cal. 


49 

The  scion  should  have  one  or  two  buds  or  eyes.  One  is  sufficient,  if 
the  nursery  in  which  they  are  planted  is  in  a  very  moist,  friable,  rich 
soil,  in  which  case  the  joining  may  be  very  near  the  surface.  But 
when  there  is  the  slightest  chance  of  drying  out,  there  should  be  at  least 
two  eyes,  in  which  case  the  junction  may  be  buried  much  deeper — in 
dry  soils.  As  has  been  already  stated,  care  should  be  taken  not  to  bury 
the  joint  too  deeply;  for  not  only  is  there  danger  of  smothering  the  graft 
from  lack  of  sufficient  air,  but  the  shoots  or  growth  will  be  imperfect. 

The  whole  question,  then,  is  one  of  the  exercise  of  common  sense.  One 
must  be  capable  of  judging  of  the  mean  between  too  dry  and  too  wet,  too 
shallow  and  too  deep.  In  all  these  operations  one  can  but  indicate  the 
general  principles,  and  the  rest  must  be  left  to  the  common  sense  of  the 
operator.  The  basis  of  all  viticulture  is,  of  course,  common  sense. 

Grafted  cuttings  which  are  made  in  April  or  before,  or  have  to  be  kept 
for  some  time,  are  always  tied  with  raffia  which  has  been  dipped  in 
bluestone,  as  before  described;  or  the  tin  or  lead  bands  and  the  blue- 
stone  raffia  may  be  used.  After  April,  the  simple,  undipped  raffia  is 
used.  In  any  case,  however,  it  must  be  remembered  that  the  bands  of 
raffia  should  not  touch  each  other,  but  a  space  should  be  left  between, 
so  that  there  may  be  free  access  of  air  to  aid  in  the  formation  of  callus. 

Heeling  In. — Grafted  cuttings  thus  made  are  either  planted  immedi- 
ately (in  April),  or  kept  until  a  more  favorable  time.  In  the  latter  case 
they  are  tied  in  bundles  of  ten  or  twenty,  and  buried  in  cool  sand,  out 
of  doors,  but  protected  from  the  rain,  frost,  and  sun.  While  they  should 
not  be  buried  so  deeply  as  to  prevent  aeration,  they  should  be  covered 
sufficiently  to  avoid  great  variations  of  temperature,  and  drying  out. 
In  other  words,  they  should  be  kept  as  were  scions  under  the  old  system. 
This  is  all  exceedingly  simple,  requiring  only  a  little  attention.  Grafted 
cuttings  in  a  moist,  sandy  place  take,  little  by  little,  the  moisture  they 
require;  the  temperature  is  then  more  constant  and  greater,  especially 
if  they  are  so  placed  as  to  be  in  the  sunshine  part  of  the  day,  in  which 
case  the  joining  tissue  will  frequently  form  before  they  are  ready  to  be 
planted  out  in  nursery.  What  must  be  avoided  is  an  excess  of  moisture, 
which  will,  it  is  true,  hasten  the  appearance  of  roots,  but  which  is  very 
unfavorable  to  the  formation  of  cicatricial  tissue  necessary  for  the 
formation  of  the  joint.  The  sand  in  which  the  grafted  cuttings  are 
preserved  should  not  contain  more  than  from  5%  to  10%  of  water. 

When  all  these  precautions  have  been  taken,  the  joint  is  almost  com- 
plete by  the  end  of  a  month,  the  scion  commencing  to  develop  and  the 
roots  to  grow.  It  is  at  this  moment  that  the  cuttings  should  be  planted 
in  nursery.  It  is  not  deemed  advisable  to  keep  the  cuttings  in  moss,  for 
many  reasons  needless  to  be  enlarged  upon  at  this  time. 


4— RV 


50  UNIVERSITY    OF    CALIFORNIA. 


NURSERIES. 

Choice  and  Preparation  of  the  Soil. — Strictly  speaking,  any  soil  can 
serve  as  a  nursery,  but  in  practice  it  has  been  found  that  those  most 
favorable  are  moist,  sandy,  or  gravelly  alluvials,  rich  in  humus  and  all 
the  plant-food  required  for  the  normal  development  of  the  vine.  Soils 
that  are  compact  naturally,  or  which  tend  to  pack  too  much,  such  as 
clay  or  adobe,  are  to  be  avoided,  as  are  all  soils  that  do  not  retain  their 
moisture  well,  or  those  that  are  not  within  the  reach  of  irrigation  water. 
There  also  may  be  mentioned  among  the  doubtful  soils,  those  that  tend 
to  bake  or  crust  over  on  the  surface.  In  case  of  a  soil  not  naturally 
rich  in  plant-food,  the  nursery  should  be  previously  well  fertilized, 
either  with  chemical  fertilizers  or  stable  manure.  It  is  not  economical 
to  plant  a  nursery  in  an  exhausted  soil,  or  one  that  is  naturally  not 
very  fertile.  The  slight  expense  of  enriching  the  small  nursery  plot 
pays  handsomely  in  the  end. 

In  all  cases  the  land  should  be  very  carefully  prepared  beforehand 
by  very  deep  and  frequent  plowing  and  cultivating.  It  has  been  shown 
that  American  vines  insist  on  deep  plowing  previous  to  being  planted 
out  in  vineyard  form;  but  in  nursery  this  is  especially  urgent.  I  have 
seen  in  this  State  some  nursery  soils  that  have  been  selected  at  the  last 
moment  when  the  soil  was  dry,  given  but  a  shallow  plowing  and  the 
vines  planted  at  once.  This  cannot  be  too  strongly  condemned. 

Some  recorded  cases  show  that  nurseries  have  been  planted  under  the 
shade  of  oak,  eucalyptus,  etc.,  trees  "  for  the  shade."  This  is  to  be 
deplored,  for  sunlight  is  very  favorable  for  the  rooting,  as  well  as  the 
callusing  of  cuttings;  trees  of  all  kinds  so  sap  the  soil  of  moisture  and 
plant-food  that  a  young  struggling  vine  cannot  be  expected  to  grow 
at  all. 

Planting. — Grafted  (as  well  as  ungrafted)  vines  should  be  planted  in 
April  or  the  beginning  of  May,  or  even  earlier,  according  to  the  locality 
and  season.  The  nursery  rows  should  be  about  2-J  feet  apart — more  or 
less  according  to  the  kind  of  plows  and  cultivators  used;  the  workmen 
should  never  be  cramped  by  too  narrow  rows,  and  in  large  nurseries  the 
rows  should  be  grouped  in  "  blocks  "  for  convenience.  The  ditches  can 
be  made  with  a  plow  and  deepened  with  a  shovel.  It  is  well  to  even  off 
the  surface  of  the  bank  on  which  the  cuttings  are  to  rest,  with  a  hoe  or 
rake.  The  cuttings  should  be  placed  on  this  sloping  bank  so  that  there 
is  good,  loose  soil  below  and  behind;  and  each  cutting  should  be  pressed 
in  so  that  no  useless  air-spaces  will  be  allowed  to  exist  and  cause  drying 
out. 

The  cuttings  should,  in  good,  well-prepared  soils,  be  so  placed  that  the 
joint  will  be  an  inch  below  the  natural  level  of  the  soil.  Then  the  most 
friable  top-soil,  carefully  pulverized,  should  be  carefully  put  on  next  to 
the  cuttings  and  the  ditch  filled ;  the  first  earth  being  packed  so  as  to 
avoid  "  air-holes."  It  is  of  course  understood  that  no  cutting  should  be 
planted  when  the  soil  is  wet.  In  cases  of  an  adobe  soil  it  is  best  to 
barely  cover  the  entire  length  of  the  cutting  with  a  layer  of  sand,  and 
then  add  the  top-soil  to  this, 

In  banking  the  cuttings  after  the  natural  level  has  been  reached, 
it  is  the  custom  to  cover  the  top  of  the  entire  cutting  at  first  with  a 


3  'S 

.     O 


RESISTANT    VINES;    THEIR    SELECTION,    ADAPTATION,    ETC.  51 

layer  of  earth  about  half  an  inch  deep.  This  will  soon  "  settle  "  and 
expose  a  very  small  part  of  the  top  of  the  cutting,  barely  exposing  the 
top  eye  or  bud,  and  thus  allowing  free  room  fo'r  the  top  growth.  Too 
deep  burying  is  as  bad  as  too  great  exposure  of  the  top,  especially  in  our 
dry  climate. 

Care  should  be  taken  to  have  thejcuttings  of  equal  length,  and  the 
ditch  of  a  uniform  depth,  so  as  to  have  the  tops  at  the  same  level. 

If  it  be  deemed  necessary  to  fertilize  the  soil  at  the  moment  of  planting, 
care  should  be  taken  not  to  put  the  fertilizer  in  immediate  contact  with 
the  cutting,  but  always  with  an  inch  or  so  of  soil  between.  If  fertiliza- 
tion is  practiced,  it  should  be  done  previously. 

In  forming  a  nursery,  one  may  have  all  the  cuttings  slope  in  the  same 
direction,  or  he  may  have  them  sloping  away  from  each  other  on 
either  side  of  a  bank,  by  making  furrows  and  turning  the  soil  toward 
each  other,  with  a  space  of  a  foot  between  the  tops  of  the  cuttings.  The 
farther  the  cuttings  are  apart,  the  better  they  will  do;  as  a  rule  they 
are  never  put  closer  than  4  inches.  All  depends,  however,  upon  whether 
the  cuttings  are  grafted  before  planting,  or  whether  they  are  to  be 
grafted  in  the  nursery,  and  especially  whether  they  are  to  remain  more 
than  a  year  in  nursery.  In  the  latter  case,  they  should  be  placed  farther 
apart  than  in  the  former. 

A  number  of  figures  are  given  illustrating  the  manner  of  planting  a 
nursery.  From  these  will  be  seen  the  manner  of  proceeding  better  than 
one  can  explain.  (See  Fig.  10.) 

Care  of  a  Nursery. — Great  care  should  be  given  to  a  young  nursery, 
in  order  to  get  the  maximum  from  the  money  invested.  One  should, 
in  the  beginning,  see  that  no  crust  is  formed  or  "  baking  "  takes  place. 
After  this,  the  weeds  should  be  kept  down,  especially  at  first.  In  order 
to  avoid  baking  after  a  rain,  a  garden  rake  in  the  hands  of  a  careful 
man  is  valuable,  the  danger  being  in  the  knocking  off  of  the  young 
shoots  in  case  of  carelessness.  If,  in  a  dry  region,  it  becomes  necessary 
to  irrigate  while  the  cuttings  are  "banked"  (that  is,  before  the  joining 
is  complete),  care  should  be  taken  that  the  water  does  not  come  in 
immediate  contact  with  the  joining  of  the  stock  and  scion.  The  exca- 
vations, or  ditches,  below  the  surface,  made  by  the  banking,  will  enable 
one  to  avoid  this  difficulty. 

Transplanting. — The  vine  resulting  from  a  grafted  cutting  is  very  apt 
at  the  end  of  the  first  growth  to  have  much  of  its  wood  badly  matured. 
It  is  then  necessary,  in  regions  where  there  is  fear  of  a  very  cold  winter, 
to  protect  the  trunk  of  the  young  vine  by  banking  the  earth  around  the 
main  part  of  it.  This  can  be  done  with  an  ordinary  plow. 

Some  prefer  to  dig  up  the  young  vines  in  November  and  bury  them 
in  piles,  deeply  covered  with  earth.  These  beds  of  rooted  vines  are 
usually  made  either  near  the  nursery  itself  or  at  any  convenient  place. 

In  digging  out  the  vines  the  greatest  attention  should  be  given  to 
determining  the  question,  "Is  there  a  good  joint?"  In  case  of  doubt, 
it  is  advisable  to  reject  the  vine.  After  a  very  few  trials  one  can  easily 
tell  whether  the  joint  is  perfect  or  not.  Taking  the  vine  in  both  hands, 
one  above  and  the  other  below  the  graft,  and  straining  it,  and  at  the 
same  time  giving  careful  examination  for  defective  spots,  will  speedily 
determine  the  value  of  the  vine.  It  is  of  far  greater  importance  to  the 


52  UNIVERSITY   OF    CALIFORNIA. 

vine-grower  to  plant  only  perfectly  grafted  vines  than  many  seem  to  sup- 
pose, if  we  may  judge  from  the  specimens  we  have  seen  in  this  State. 
It  is  not  the  cost  of  the  poorly-grafted  and  rejected  vine  that  should 
be  considered.  This  is  insignificant  when  compared  with  the  great 
amount  of  time  and  actual  cash  lost  in  planting  and  cultivating  the 
land  around  the  doubtful  vine  for  from  one  to  six  years  before  it  is  dis- 
covered that  the  graft  is  so  defective  that  the  whole  vine  must  be  dug 
out  or  regrafted.  It  will  be  noted  in  the  grafted  vineyards  in  this  State 
that  very  frequently  a  badly-joined  vine  may  be  able  to  support  the 
first  few  years  of  growth  so  well  that  one  would  never  suppose  that 
there  was  a  defect  in  the  graft,  especially  if  the  roots  be  neglected  on 
the  scion,  as  is  frequently  the  case.  About  the  time  the  phylloxera 
begins  to  attack  the  neglected  roots  on  the  non-resistant  scion,  and  the 
vine  comes  into  full  bearing  and  requires  more  support  than  ever,  is  the 
time  when  the  vine-grower  begins  to  neglect  cultivation  a  little,  on  the 
plea  that  the  vines  are  well  started,  and  are  able  to  "  stand  it  better  "; 
this  is  also  the  time  when  sudden  seemingly  inexplicable  failures  of 
resistant  vineyards  are  recorded.  The  vineyardist  could  prevent  more 
actual  cash-loss  than  he  is  aware  of,  if  he  would  but  test  each  joint  and 
mercilessly  reject  everything  that  is  not  perfect.  This  point  is  dwelt  on 
somewhat  at  length  because  it  is  one  that  is  of  vital  importance,  and 
one  that  is  most  frequently  ignored. 

In  planting  young  rooted  vines  great  care  should  be  given  to  the 
operation,  or  loss  will  result.  As  has  been  said,  the  American  vine 
insists  on  greater  care  in  planting  and  in  the  preparation  of  the  soil  than 
the  European  vines.  Unless  the  vine-planter  is  prepared  to  give  it 
this  extra  care  and  attention,  he  is  strongly  advised  not  to  plant  vines 
at  all,  for  he  will  surely  lose  the  money  invested. 

The  soil  should  have  been  plowed  at  least  once,  with  a  four-horse 
sulky  plow,  as  deep  as  the  plow  can  be  'driven — even  if  a  couple  of 
extra  horses  have  to  be  called  in  to  pull  it.  It  is  of  course  an  expen- 
sive operation,  but  it  pays,  and  pays  well,  to  incur  it.  As  before 
remarked,  land  thus  prepared  will  yield  paying  crops  two  years  sooner 
than  if  the  ordinary  method  of  plowing  be  pursued,  besides  avoiding 
the  risk  of  the  loss  of  the  entire  vineyard.  The  poorer  the  land  the 
deeper  it  should  be  plowed,  and  the  more  compact  the  land  the  deeper 
it  should  be  plowed.  As  has  been  remarked,  this  is  no  theory  of  the 
writer,  but  a  fact  established  beyond  the  possibility  of  rational  doubt. 

The  vines  are  planted  at  the  usual  distance,  except  that  in  the  case  of 
planting  a  resistant  vineyard  on  the  same  soil  that  has  for  years  nour- 
ished another  one,  care  should  be  taken  not  to  plant  in  the  same  holes 
from  which  vines  were  dug,  but  in  the  middle  of  the  space  between  the 
rows.  And  it  is  also  as  well  to  previously  fertilize  the  land,  for  it  must 
be  remembered  that  the  roots  of  the  young  vine  are  too  short  and  as  yet 
too  feeble  to  search  for  all  the  food  the  plant  requires;  so  that  in  start- 
ing it  should  be  aided. 

The  holes  should  be  dug  with  a  shovel  or  spade.  The  custom  of  using 
a  "  post-hole  digger "  or  a  crowbar,  or  merely  opening  a  slight  space 
with  a  shovel  and  jamming  the  roots  down  behind  the  shovel,  are 
common  customs  in  certain  places.  These  customs  cannot  be  too 
severely  condemned.  They  are  responsible  for  the  loss  of  enormous 
sums  of  money  to  the  State.  Holes  should  be  as  carefully  dug  as  for 
fruit  trees  or  any  kind  of  valuable  plant.  There  should  be  plenty  of 


FIG.  II. 


FIG.  12. 


Fig.  11.    A  six-year-old  vine  badly  grafted,  perishing  from  phylloxera  on  roots  from 
scion. 

Fig.  12.    Old  grafted  vine  showing  almost  normal  difference   between  size  of  stock 
and  scion. 


FIG.  13. 
Fig.  13.    Rupestris  cutting-stock,  showing  manner  of  removing  eyes. 


RESISTANT   VINES;    THEIR    SELECTION,    ADAPTATION,    ETC.  53 

loose  soil  at  the  bottom  of  the  hole,  and  there  should  be  plenty  of  room 
on  the  sides.  Above  all,  the  roots  should  be  so  arranged  that  they  will 
not  cling  together  in  a  "  rope  "  or  be  bent  upward  (as  I  have  seen  so  often 
the  case) ;  but  they  should  be  given  a  downward  slope,  so  that  they  will 
at  once  "  go  down,"  especially  in  the  case  of  dry  ground.  Some  have 
found  that  in  such  dry  soil  it  pays  to  put  in  the  bottom  of  the  hole, 
six  inches  below  the  roots,  a  shovelful  of  well-rotted  stable  manure. 
This  prevents  the  roots  from  going  along  the  surface,  as  some  of  the 
species  tend  to  do  naturally,  and  at  the  same  time  shuts  out  the  danger 
of  being  torn  by  the  plow,  or  affected  by  slight  droughts. 

After  the  second  year  the  American-rooted  vineyard  will  be  found  to 
require  extra  care,  and  will  be  found  to  yield  heavier  crops  than  ever 
were  produced  by  the  same  varieties  on  their  own  roots.  For  the  first 
two  years,  and  in  some  cases  for  three,  the  roots  of  the  scion  should 
be  removed  annually.  After  three  years  this  will  not  be  necessary.  If 
it  is  neglected  the  scion  will  grow  entirely  away  from  the  stock,  and  then, 
when  the  phylloxera  attacks  the  roots  of  the  scion,  the  vine  becomes  so 
enfeebled  that  nothing  can  be  done  with  it. 


o 


UNIVERSITY  OF  CALIFORNIA. 

AGRICULTURAL  EXPERIMENT  STATION. 

BERKELEY,   CAL. 


E.   W.    HILGARD,    DIRECTOR.  BULLETIN    No.  119. 

DECEMBER,  1897. 


VINE   PRUNING. 

BY  F.  T.  BIOLETTI. 


The  literature  relating  to  the  pruning  and  training  of  the  vine  is 
already  very  voluminous,  but  there  seems  to  be  no  one  work  which 
treats  the  subject  in  a  thorough  and  convenient  way  for  California 
vine-growers.  Publications  in  English  refer  generally  to  methods 
suited  to  the  Eastern  States  or  to  hot-house  cultivation,  while  for- 
eign publications,  besides  being  more  or  less  inaccessible,  treat  the 
subject  30  widely  that  the  grower  is  at  a  loss  what  to  choose  from 
such  a  mass  .of  material.  It  is  the  purpose  of  this  Bulletin,  there- 
fore, to  present  a  brief  summary  of  what  in  foreign  methods  seems 
useful  and  applicable  to  California  conditions,  together  with  the 
results  of  experiments  on  the  University  of  California  vine  plots,  and 
of  observations  made  in  numerou  s  vineyards  in  various  regions  of 
the  State. 

Almost  every  vine-growing  district  has  its  peculiar  systems  of 
training,  ranging  from  the  non-training  usual  in  parts  of  Italy,  where 
the  vine  spreads  almost  at  will  over  trees  planted  for  the  purpose,  to 
the  acme  of  mutilation  practiced  in  many  localities  where  the  vine 
is  reduced  to  a  mere  stump  barely  rising  above  the  surface  of  the 
ground.  These  various  systems  will  not  be  discussed  here,  but  only 
those  which  experience  has  shown  to  be  most  adapted  to  California 
conditions. 

No  account,  however  detailed,  of  any  system  can  replace  the  in- 
telligence of  the  cultivator.  For  this  reason  the  general  principles  of 
plant  physiology  which  underlie  all  proper  pruning  and  training  are 
discussed  in  connection  with  the  several  systems  described.  This 
should  aid  the  grower  in  choosing  that  system  most  suited  to  the  con- 
ditions of  his  vineyard,  and  to  modify  it  to  suit  special  conditions 


and  seasons.  All  the  operations  of  pruning,  tying,  staking,  etc.,  to 
which  a  cultivated  vine  owes  its  form,  are  conveniently  considered 
together. 

No  cultivated  plant  is  susceptible  of  such  a  variety  of  modes 
of  training  as  the  vine,  and  none  can  withstand  such  an  amount  of 
abuse  in  this  matter  and  such  radical  interference  with  its  natural 
mode  of  growth.  On  the  other  hand,  no  other  plant,  perhaps,  is  so 
sensitive  to  proper  treatment,  or  responds  so  readily  to  a  rational 
mode  of  pruning  and  training. 

OBJECTS  OF  PRUNING.— The  objects  of  pruning  are  (a) 
to  facilitate  cultivation  and  gathering,  (b)  to.  increase  the  average 
yield,  and  (c)  to  improve  the  quality  of  fruit.  The  vine  must  not 
be  trained  so  high  that  the  grapes  are  difficult  to  gather,  nor  al- 
lowed to  spread  its  arms  so  wide  that  the  cultivation  of  the  ground 
is  unduly  interfered  with.  Vines  untouched  by  the  pruner's  knife 
bear  irregularly;  a  year  of  over-bearing  being  followed  by  several  of 
under-bearing  as  a  consequence  of  exhaustion  caused  by  a  too  severe 
drain  on  the  reserve  forces  of  the  plant.  The  grapes  on  untrained  or 
improperly  trained  vines  are  exposed  to  different  conditions  of  heat 
and  light,  and  consequently  develop  and  ripen  unevenly. 

PHYSIOLOGICAL  PRINCIPLES.— The  main  facts  regard- 
ing the  physiology  of  the  vine  to  be  kept  in  mind  in  this  connection 
are  : 

1.  The  vine  feeds  by  means  of  the  green  coloring  matter  (chloro- 
phyll) of  its  leaves.     It  obtains  the  sugar,  starch,  etc.,  which  it  needs 
from  the  carbonic  acid  of  the  air    which  is  converted  into  these  sub- 
stances by  the  chlorophyll  under  the  influence  of  light.      A    certain 
amount  of  green  leaf  surface  functioning  for  a  certain  time  is  neces- 
sary to  produce  sufficient  nourishment  for  the  vital  needs  of  the  vine 
and  for  the  production  of  a  crop.     Those  leaves  most  exposed  to  the 
direct  rays  of  the  sun  are  most  active     in     absorbing    food.       The 
youngest  leaves  take  all  their  nourishment  from  the  older  parts    of 
the  plant:  somewhat  older  leaves  use  up  more  nutrient  material    in 
growing  than  they  absorb  from  the  air.    A  young  shoot  may  thus  be 
looked  upon  as,  in  a  sense,  parasitic  upon  the  rest  of  the  vine.    The 
true  feeders  of  the  vine  and  of  its  crop    are    the    mature,    dark-green 
leaves. 

2.  Within  certain  limits  the  fruitfulness  of  a  vine  or  of  a  part 
of  a  vine  is  inversely  proportional  to  its  vegetative  vigor.     Methods 
which  tend  to  increase  the  vegetative  vigor  of  a  vine  or  of  a  part 
of  a  vine  tend  to  diminish  its  bearing  qualities,  while,   on  the  con- 
trary, anything  which  diminishes  vegetative  vigor  tends  to  increase 
fruitfulness.     Failure  to  reckon  with  this   fact    and    to    maintain    a 
proper   mean  between  the  two  extremes  leads,  on  the  one  hand,  to 
comparative  sterility,  and,  on  the  other,  to  over-bearing  and  prema- 
ture exhaustion. 

3.  The  vine  tends  to  force  out  terminal  buds  and  to  expend  most 
of  its  energy  on  the  shoots  farthest  from  the  trunk.     To  keep  the 
vine  within  practical  limits,  this  tendency  must  be  controlled  by  the 
removal  of  the  terminal  buds,  or  bv  measures  which  check  the  flow 
of  sap   and  force  the  growth  of  buds  nearer  the  stock. 


4.  The  nearer  a  shoot  approaches  the  vertical  the  more  vigorous 
it  will  be. 

5.  The  size  of  shoots  and  of  fruit   is,  within   certain    limits,   in- 
versely as  their  amount.     That  is,  with  a  given  vine,  or  arm  of  a 
vine,  the  fewer  shoots  allowed  to  grow  the  larger  each  will  be,  and 
the  same  is  true  of  bunches  of  fruit. 

6.  Other  conditions  being  equal,  an  excess  of  foliage  is  accom- 
panied by  a  small  amount  of  fruit;  an  excess  of  fruit' by  diminished 
foliage. 

7.  Shoots  coming  from  one-year-old  wood  growing  out  of  two- 
year-old  wood  are  alone  to  be  depended  on  for  fruit.    Other  shoots  are 
usually  sterile. 


, ,'  8.  Bending,  twisting  or  otherwise  injuring  the  tissues  of  the 
vine  or  its  branches  tend  to  diminish  its  vegetative  vigor,  and  there- 
fore, unless  excessive,  to  increase  its  fertility. 

A  description  of  a  typical  vine  giving  the  names  of  the  principal 
parts,  will  make  clear  the  accounts  of  methods  to  be  given  later. 
Fig.  i  represents  a  vine  of  no  particular  order  of  pruning,  showing 
the  various  parts.  The  main  body  of  the  vine  (T)  is  called  the 
trunk  or  stem;  the  principal  divisions  (B)  branches;  the  smaller  di- 
visions (A)  arms,  and  the  ultimate  ramifications  (C)  shoots  when 
green,  and  canes  when  mature.  A.  shoot  growing  out  of  the  vine 
above  ground  on  any  part  older  than  one  year  (WS)  is  called  a 
water  sprout.  Shoots  coming  from  any  part  of  the  vine  below 
ground  (S)  are  called  suckers.  When  a  cane  is  cut  back  to  I,  2,  3, 
or  4  eyes  it  is  called  a  spur  (R). 

When  a  shoot  or  cane  of  one  season  sends  out  a  secondary  shoot 
the  same  season,  the  latter  (L)  is  called  a  lateral. 

Fig.  II  represents  an  arm  of  a  vine  as  it  appears  in  winter  after 
the  leaves  have  fallen.  The  canes  (Wi)  are  the  matured  shoots  of 
the  previous  spring.  W2,  W3,  W4  represent  2,  3,  and  4-year-old 
wood  respectively.  Near  the  base  of  each  cane  is  a  basal  bud  or 
eye  (B°).  In  counting  the  number  of  eyes  on  a  spur  the  basal  eye 
is  not  included.  A  cane  cut  at  Ki  for  instance  leaves  a  spur  of 
one  eye,  at  K.2  a  spur  of  two  eyes  and  so  on.  When  more  than  four 
eyes  are  left  the  piece  is  generally  called  a  fruiting  cane  (Fig.  I,  F). 
The  canes  (C,Ci)  coming  from  two-year  old  wood  (W2)  possess 


fruit  buds;  that  is,  they  are  capable  of  producing  fruit  -  bearing 
shoots.  Water  sprouts  (WS)  and  suckers  (S)  do  not  ordinarily 
produce  fruit-bearing  shoots.  Below  the  basal  bud  each  cane  has 
one  or  more  dormant  buds  (b  Fig.  Ill)  which  do  not  grow  unless 
the  number  of  eyes  left  by  pruning  or  frost  is  insufficient  to  relieve 


c 


the  excess  of  sap  pressure.  These  buds  produce  sterile  shoots. 
Each  eye  on  a  cane  has,  at  its  base,  two  dormant  buds.  One  of  these 
sometimes  grows  out  the  year  it  is  formed,  making  a  lateral  (L, 
Figs.  I,  II).  These  laterals  may  send  out  secondary  laterals  (SL, 
Fig.  I).  It  is  on  the  laterals  and  secondary  laterals  jthat  the  so-called 
second  and  third  crops  are  borne. 

PRUNING  FOR  WOOD  AND  FOR  FRUIT.— One  of  the 
chief  aims  of  pruning  is  to  maintain  a  just  equilibrium  between  vege- 
tative vigor  and  fertility.  We  must,  then,  prune  for  both  wood  and 
fruit.  A  vine  which  has  become  enfeebled  by  over-bearing  should 
be  pruned  for  wood.  By  this  is  meant  that  only  a  small  number  of 
buds  should  be  left.  As  all  the  energies  of  the  vine  have  to  be  ex- 
pended on  a  small  number  of  shoots,  these  shoots  grow  with  more 
than  ordinary  vigor.  Under  these  conditions  the  vine  bears  little; 
first,  because  the  eyes  near  the  bases  of  the  canes,  which  are  the  only 
ones  left  in  very  short  pruning,  are  naturally  less  fruitful  than  those 
farther  removed  from  the  main  body  of  the  vine;  and  second,  because 
an  exceptionally  vigorous  shoot  is  generally  sterile.  The  vine  is  thus 
strengthened,  and,  as  the  stores  of  nutriment  provided  by  a  vigorous 
vegetation  are  not  drawn  upon  by  a  heavy  crop,  the  increased  vigor 
of  the  vine  is  more  marked  the  second  year.  The  second  year,  there- 
fore, more  wood  may  be  left  and  the  crop  increased  without  detri- 
ment to  the  vine. 

On  the  other  hand,  a  vine  which  "  goes  to  wood  "  must  be 
pruned  for  fruit.  For  this  purpose  we  increase  the  number  of  buds 
left  and  choose  the  most  fruitful  wood.  The  largest  canes  are  the 
least  fruitful,  while  the  smallest  have  not  the  necessary  vigor  to  sup- 


-De- 


a large  crop.     The  best  cane  to  leave  for  fruit  then  is  one  of 
medium  size,  with  well-formed  eyes. 

PROPER  METHOD  OF  MAKING  CUTS.— It  is  by  no 
means  a  matter  of  indifference  just 
where  the  cut  is  made  in  removing 
a  cane  or  arm.  This  will  be  made 
clearer  by  referring  to  Eig.  III. 
The  upper  part  of  the  spur  is  rep- 
resented as  split  in  two  longitudi- 
nally in  order  to  show  the  internal 
structure  of  the  cane.  It  will  be 
noted  that  at  each  bud  there  is  a 
slight  swelling  of  the  cane.  This 
is  called  a  node,  and  the  space  be- 
tween an  internode.  The  inter- 
nodes  are  filled  with  soft  pith,  but 
at  each  node  there  is  a  growth  of 
hard  wood  extending  through  the 
cane.  Now,  if  the  cane  be  cut  oft 
at C i,  in  the  middle  of  an  internode, 
the  pith  will  shrink  away  and  leave 
a  little  hollow  in  which  the  rain 
collects.  This  is  an  excellent  breed- 
ing place  for  fungi  and  bacteria, 
which  cause  rotting  of  the  pith  and 
frequently  kill  the  bud.  If,  on  the  contrary,  the  cane  be  cut  at  «C2, 
through  a  node,  a  protecting  cover  of  hard  wood  is  left,  which  is  an 
effectual  barrier  against  decay  organisms.  If  a  spur  projects  too 
far  from  the  vine  and  it  is  desirable  to  make  it  as  short  as  possible 
in  order  not  to  interfere  with  cultivation,  it  should  be  cut  at  C  and 
the  cut  made  as  nearly  vertical  as  possible.  This  allows  the  water 
to  run  off,  and  leaves  less  pith  to  foster  the  growth  of  the  fungi.  At 
the  base  of  the  cane  there  is  a  slight  enlargement  (E).  In  removing 
a  cane  completely  the  cut  should  be  made  just  above  this  enlarge- 
ment. This  is  the  most  favorable  place  for  healing,  as  it  makes  the 
smallest  possible  wound  and  does  not  leave  a  projecting  stump  of 
dead  wood  to  prevent  the  healing  tissues  from  closing  over  the 
wound.  In  removing  a  piece  of  older  wood,  as  at  K°  and  Ti,  Fig. 
II,  it  is  advisable  not  to  cut  too  close  for  fear  of  injuring  the  spur 
by  the  drying  out  of  the  wood.  The  projecting  pieces  of  dead 
wood  left  in  this  way  should  be  carefully  removed  the  next  year  in 
order  to  allow  the  wound  to  heal  over.  The  large  cuts  which  are 
thus  occasionally  necessary  are  most  easily  performed  by  means  of  a 
well-made  and  well-sharpened  pair  of  two-hand  pruning  shears.  These 
shears  are  often  to  be  preferred  to  the  ordinary  one-hand  shears  be- 
cause they  render  the  cutting  through  the  nodes  easier  and  do  away 
almost  entirely  with  the  necessity  of  a  saw.  Of  course,  a  careless 
workman  may  split  and  injure  vines  seriously  by  using  long-han- 
dled shears  clumsily,  but  the  bending  of  arms  to  facilitate  cutting 
with  the  one-hand  shears  often  results  in  the  same  evil.  The  one- 
hand  shears,  however,  are  more  convenient  when  many  long  fruit- 


ing  canes  are  left,  as  the  necessary  trimming  off  of  tendrils  and  lat- 
erals is  more  easily  performed  with  them. 

SHORT  AND  LONG  PRUNING.  —  The  winter-pruning  of 
the  vine  consists  in  cutting  off  a  certain  amount  of  the  mature  wood 
of  the  immediately  preceding  season's  growth  (canes),  and  occa- 
sionally of  the  older  wood.  The  main  problem  of  winter-pruning, 
then,  resolves  itself  into  determining  how  much  and  what  wood  shall 
be  left.  In  all  kinds  of  pruning  most  of  the  canes  are  removed  en- 
tirely. In  short-pruning,  the  remainder  are  cut  back  to  spurs  of  one, 
two  or  three  eyes.  The  number  of  spurs  is  regulated  by  the  vigor 
and  age  of  the  vine.  This  mode  of  pruning  can  be  used  only  for 
varieties  in  which  the  eyes  near  the  base  of  the  cane  are  fruitful. 
For  all  other  cases  long  or  half-long  pruning  is  necessary. 

In  half -long  pruning  certain  canes  are  left  with  from  four  to  -  six 
eyes,  according  to  the  length  of  the  internodes.  These  canes  or  fruit- 
spurs  will  bear  more  fruit  than  short  spurs  for  three  reasons:  I,  be- 
cause there  will  be  more  fruit-bearing  shoots;  2,  because  the  upper 
eyes  are  more  fruitful  than  the  lower;  and  3,  because  a  larger  num- 
ber of  eyes  being  supplied  with  sap  from  the  same  arm,  each  shoot 
will  be  less  vigorous  and  therefore  more  fruitful.  Owing,  however, 
to  the  tendency  of  the  vine  to  expend  the  principal  part  of  its  vigor 
on  the  shoots  farthest  removed  from  the  base  of  the  canes,  the  lower 
eyes  on  the  long  spurs  will  generally  produce  very  feeble  shoots.  In 
order,  then,  to  obtain  spurs  of  sufficient  vigor  for  the  next  year's  crop 
it  would  be  necessary  to  choose  them  near  the  ends  of  the  long  spurs 
of  the  previous  year,  if  no  others  were  left.  This  would  result  in  a 
rapid  and  inconvenient  elongation  of  the  arms.  In  order  to  avoid 
this  it  is  necessary  to  leave  a  spur  of  one  or  two  eyes  below  each 
long  fruiting  spur,  that  is  to  say,  nearer  the  trunk.  These  short  wood 
spurs  having  only  one  or  two  eyes,  will  produce  vigorous  canes  for 
the  following  year,  and  the  spurs  which  have  borne  fruit  may  be  re- 
moved altogether,  thus  preventing  an  undue  elongation  of  the  arms. 
In  half-long  pruning,  however,  it  is  very  hard  to  retain  the  proper 
equilibrium  between  vigor  and  fruitfulness.  If  a  little  too  much  wood 
is  left  the  shoots  from  the  wood  spurs  will  not  develop  sufficiently,  and 
the  next  year  we  have  to  choose  between  leaving  small  under-sized 
spurs  near  the  trunk  and  spurs  of  proper  size  too  far  removed  from 
the  trunk.  In  long  pruning  this  difficulty,  as  will  be  seen,  is  to  a 
great  extent  avoided. 

In  long  pruning  the  fruit  spurs  of  half-long  pruning  are  re- 
placed by  long  fruit  canes.  These  are  left  two  or  three  feet  long,  or 
longer.  The  danger  here  that  the  vine  will  expend  all  its  energies 
on  the  terminal  buds  of  these  long  canes  and  leave  the  eyes  of  the 
wood  spurs  undeveloped  is  still  greater  than  in  half-long  pruning. 
This  difficulty  is  overcome  by  bending  or  twisting  the  fruit  canes  in 
some  manner.  This  bending  causes  a  certain  amount  of  injury  to  the 
tissues  of  the  canes,  which  tends  to  check  the  flow  of  sap  towards 
their  ends.  The  sap  pressure  thus  increases  in  the  lower  buds  and 
forces  them  out  into  strong  shoots  to  be  used  for  spurs  for  the  next 
pruning.  The  bending  has  the  further  effect  of  diminishing  the  vigor 
of  the  shoots  on  the  fruit  canes  and  thus  increasing  their  fruitfulness. 


This  principle  of  increase  of  fruitfulness  by  mechanical  injury 
is  very  useful  if  properly  understood  and  applied.  It  is  a  well-known 
fact  that  vines  attacked  by  phylloxera  or  root  rot  will  for  one  year 
bear  an  exceptionally  large  crop  on  account  of  the  diminution  of 
vigor  caused  by  the  injury  to  their  roots.  A  vine  also  which  has  been 
mutilated  by  the  removal  of  several  large  arms  will  often  produce 
heavily  the  following  year.  In  all  these  cases,  however,  the  transient 
gain  is  more  than  counter-balanced  by  the  permanent  injury  and 
loss.  The  proper  application  of  the  principle  is  to  injure  tissues  only 
of  those  parts  of  the  plant  which  it  is  intended  to  remove  the  next 
year  (fruit  canes),  and  thus  increase  fruitfulness  without  {icing  any 
permanent  injury  to  the  plant. 

PRUNING  OF  YOUNG  VINES.— When  a  rooted  vine 
is  first  planted,  it  should  be  cut  back  to  two  eyes.  If  the 
growth  is  not  very  good  the  first  season,  all  the  canes  but 
one  should  be  removed  at  the  first  pruning,  and  that  one 
left  with  two  or  three  eyes,  according  to  its  strength.  The 
next  year,  or  the  same  year  in  the  case  of  strong  grow- 
ing vines  in  rich  soil,  the  strongest  cane  should  be  left  about  12 
inches  long  and  tied  up  to  the  stake  The  next  year  two  spurs  may  be 
left,  of  two  or  three  eyes  each.  These  spurs  will  determine  the  posi- 
tion of  the  head  or  place  from  which  the  arms  of  the  vine  spring.  It 
is  important,  therefore,  that  they  should  be  chosen  at  the  right  height 
r'rom  the  ground.  From  ten  to  twenty  inches  is  about  the  right 
height;  the  lowest  for  dry  hillsides  where  there  is  no  danger  of  frost; 
the  highest  for  rich  bottom  lands  where  the  vine  will  naturally  grow 
large.  Vines  grown  without  stakes  will  have  to  be  headed  lower  than 
this  in  order  to  make  them  support  themselves.  In  the  following  few 
years  the  number  of  spurs  should  be  increased  gradually,  care  being 
taken  to  shape  the  vine  properly  and  to  maintain  an  equal  balance  of 
the  arms. 

In  general,  young  vines  are  more  vigorous  than  old,  and  tend 
more  to  send  out  shoots  from  basal  and  dormant  buds.  They  should, 
therefore,  be  given  more  and  longer  spurs  in  proportion  than  older 
vines.  They  also  tend  to  bud  out  very  early  in  the  spring,  and  are 
thus  liable  to  be  frost-bitten.  For  this  reason  they  are  generally 
pruned  late  (March)  in  frosty  locations.  This  protects  them  in  two 
ways.  In  the  first  place,  in  unpruned  vines  the  buds  near  the  ends  of 
the  canes  start  first  and  relieve  the  sap  pressure,  and  though  these 
are  caught  by  the  frost  the  buds  near  the  base,  not  having  started, 
are  saved.  In  the  second  place,  the  pruning  being  done  when  the  sap 
is  flowing  there  is  a  loss  of  sap  from  the  cut  ends  of  the  spurs  which 
further  relieves  the  sap  pressure  and  retards  the  starting  of  the  lower 
eyes.  This  method  of  preventing  the  injury  of  spring  frosts  by  very 
late  pruning  has  been  tried  with  bearing  vines,  but  is  very  injurious. 
Older  vines  being  less  vigorous  are  unable  to  withstand  the  heavy 
drain  caused  by  the  profuse  bleeding  which  ensues;  and  though  no 
apparent  damage  may  be  done  the  first  year,  if  the  treatment  is 
continued  they  may  be  completely  ruined  in  three  or  four  years. 

.  SYSTEMS  OF  PRUNING. 

The  systems  of  pruning  adapted  to  vineyards  in  California  may 
be  divided  into  six  types  according  to  the  form  c,-'\en  to  the  main 
body  of  the  vine  t\nd  the  length  of  the  spurs  and  fruiting  canes. 


A.  Vine  pruned  to  a  head,  with  short  arms. 

I.  With  spurs  of  two  or  three  eyes  only  (short  pruning). 

II.  With  wood  spurs  of  one  or  two  eyes  and  fruit  spurs  of  four, 
to  six  eyes  (half-long  pruning;. 

III.  With  wood  spurs  of  one  or  two  eyes  and  long   fruit   canes, 
(long-pruning). 

B.  Vine  with  a  long  horizontal  branch  or  continuation  of  the  trunk. 

IV.  With  spurs  of  two  or  three  eyes  only  (short  pruning). 

V.  Wjth  wood  spurs  of  one  or  two  eyes  and  fruit  spurs  of    four 
to  six  eyes  (half-long  pruning). 

VI.  With  wood  spurs  of  one  or  two  eyes  and  long  fruit  canes 
(long-pruning). 

These  types  are  applicable  to  different  varieties  of  vines  according 
— (i)  To  the  natural  stature  of  the  vine — that  is  to  say,  whether  it  is 
a  large  of  small  grower  and  tends  to  make  a  large,  extended  trunk  or 
a  limited  one. — (2)  To  the  position  of  the  fruit  buds.  In  some  varieties 
all  the  buds  of  the  canes  are  capable  of  producing  fruitful  shoots,  while 
in  others  the  one,  two  or  three  buds  nearest  the  base  produce  only 
sterile  shobts. — (3)  To  the  size  of  the  individual  bunches.  It  is 
necessary  in  order  to  obtain  a  full  crop  from  a  variety  with  small 
bunches  to  leave  a  larger  number  of  eyes  than  is  necessary  in  the  case 
of  varieties  with  large  bunches. 

What  type  or  modification  of  a  type  shall  be  adopted  in  a  par- 
ticular instance  depends  both  on  the  variety  of  vine  and  on  the  nature 
of  the  vineyard.  A  vine  growing  on  a  dry  hillside  must  not  be  pruned 
the  same  as  another  vine  of  the  same  variety  growing  on  rich  bottom 
land.  In  general,  vines  on  rich  soil,  where  they  tend  to  grow  large 
and  develop  abundant  vegetation,  should  be  given  plenty  of  room  and 
allowed  to  spread  themselves,  and  should  be  given  plenty  of  fruiting 
buds  in  order  to  control  their  too  strong  inclination  to  ''go  to  wood." 
Vines  on  poor  soil,  on  the  contrary,  should  be  planted  closer  togeth- 
er and  pruned  shorter,  or  with  fewer  fruiting  buds,  in  order  to  main- 
tain their  vigor. 

Type  I. — This  is  the  ordinary  short  pruning  practiced  in  90  per 
cent  of  the  vineyards  of  California,  and  is  the  simplest  and  least  ex- 
pensive manner  of  pruning  the  vine.  It  is,  however,  suited  only  to 
vines  of  small  growth,  which  produce  fruitful  shoots  from  the  lowest 
buds,  and  of  which  the  bunches  are  large  enough  to  admit  of  a  full 
crop  from  the  small  number  of  buds  which  are  left  by  this  method. 
The  chief  objection  to  this  method  for  heavily  bearing  vines  is  that 
the  bunches  are  massed  together  in  a  way  that  favors  rotting  of  the 
grapes  and  exposes  the  different  bunches  unequally  to  light  and  heat. 

Fig.  IV.  represents  the  simplest  form  of  this  style  of  pruning. 
The  vine  should  be  given,  as  nearly  as  possible,  the  form  of  a  goblet, 
slightly  flattened  in  the  direction  of  the  rows.  It  is  important  that  the 
vine  be  kept  regular  and  with  equally  balanced  arms.  This  is  the  chief 
difficulty  of  the  method  and  calls  for  the  exercise  of  some  judgment. 
From  the  first,  the  required  form  of  the  vine  should  be  kept-  in  view. 
On  varieties  with  a  trailing  habit  of  growth  vertical  spurs  must  be 


chosen,  and  with  some  upright  growers  it  will  be  found  necessary  to 
choose  spurs  nearer  the  horizontal. 

The  arms  must  be  kept  short  for  convenience  of  cultivation  and 


to  give  them  the  requisite  strength  to  support  their  crop  without 
bending  or  breaking.  For  this  reason  the  lowest  of  the  two  or  three 
canes  coming  from  last  year's  spur  should  be  left.  For  instance,  on 
Fig.  II  the  cane  should  be  cut  at  K2  or  K/3,  according  as  two  or 
three  eyes  are  needed,  and  the  rest  of  the  arm  removed  at  K°.  As 
even  with  the  greatest  care  some  arms  will  become  too  long  or  pro- 
ject in  wrong  directions,  it  is  necessary  to  renew  them  by  means  of 
canes  from  the  old  wood  or  water  sprouts.  For  instance,  if  the  other 
arm  represented  on  Fig.  II  were  too  long,  it  should  be  removed  and 
replaced  by  another  developed  from  the  cane  (WS).  As  the  cane 
comes  from  three-year-old  wood  it  cannot  be  depended  on  to  pro- 
duce grapes.  "For  this  reason  it  is  best  the  first  year  to  prune  the 
arm  at  T,  leaving  a  spur  for  fruit,  and  cut  the  water  sprout  ait  T  °  leav- 
ing a  wood  spur  of  one  eye.  The  next  year  the  cane  coming  from 
the  first  eye  of  WS  can  be  left  for  a  fruit  spur,  and  the  arm  removed 
at  Ti.  The  cutting  back  of  an  elongated  arm  should  not  be  deferred 
too  long,  as  the  removal  of  old  arms  leaves  large  wounds  which  weak- 
en the  vine  and  render  it  liable  to  attacks  of  fungi. 

In  order  to  maintain  the  equilibrium  of  the  arms  it  is  often  nec- 
essary to  prune  back  the  more  vigorous  arms  severely  in  order  to 
throw  the  strength  of  the  vine  into  the  weaker  arms.  If  the  vine  ap- 
pears too  vigorous,  that  is  if  it  appears  to  be  "going  to  wood"  at  the 
expense  of  the  crop,  two  spurs  may  be  left  on  some  or  all  of  the  arms. 
In  this  case  the  upper  spur  should  be  cut  above  the  third  eye  (K4 
Fig.  n),  and  the  lower  above  the  first  or  second  (Ki  or  K.2).  This 
will  cause  the  bulk  of  the  fruit  to  be  borne  on  the  upper  spur,  and  the 
most  vigorous  shoots  to  be  developed  on  the  lower,  which  provides  the 
wood  for  the  following  year.  This  is  an  approach  to  the  next  (half- 
long)  method  of  pruning. 

Type  II. — Vines  which  require 
more  wood  than  can  well  be  given 
by  ordinary  short  pruning,  or  of 
which  the  lower  eyes  are  not  suffi- 
ciently productive,  may  in  some 
cases  be  pruned  in  the  manner  il- 
lustrated by  Fig.  V.  For  some  va- 
rieties it  is  necessary  to  leave  spurs 
of  only  three  eyes,  as  at  S;  for 
others,  short  canes  of  four  or  five 


10 


eyes  must  be  left,  as  at  CC.  These  shorter  spurs  can  be  left  without 
support,  but  the  longer  ones  require  some  arrangement  to  prevent 
their  bending  over  with  the  weight  of  fruit  and  destroying  the  shape 
of  the  vine.  In  some  cases  simply  tying  the  ends  of  the  canes  to- 
gether will  support  them  fairly  well,  but  it  is  better  to  attach  them  to 
a  stake  and  bend  them  at  the  base  a  little  when  possible  in  order  to 
retard  the  flow  of  sap  to  the  ends.  It  is  very  necessary  to  leave  strong 
spurs  of  one  eye  (not  counting  the  basal  eye)  in  order  to  provide 
wood  for  the  following  year.  At  the  pruning  following  the  one 
represented  in  the  cut  the  fruiting  part  of  the  arms  will  be  removed 
at  KK  and  a  new  fruiting  spur  or  cane, made  of  the  cane  which  comes 
from  the  eye  on  the  wood  spurs  W.  The  basal  bud  on  W  will  in  all 
probability  have  produced  a  cane  which  can  be  cut  back  to  one  eye  to 
furnish  a  new  wood  spur.  If  this  is  not  the  case  it  shows  that  too 
much  wood  was  left  the  first  year,  and  therefore  no  fruit  cane  should 
be  left  on  this  arm,  but  only  a  single  spur  of  two  or  three  eyes.  This 
will  be  a  return  to  short  pruning,  and  must  be  resorted  to  whenever 
the  small  size  of  the  canes  or  the  failure  to  produce  replacing  wood 
near  the  head  of  the  vine  shows  that  the  vigor  is  diminishing.  If,  on 
the  contrary,  the  arm  shows  an  abundance  of  vigorous  canes,  proving 
that  the  vine  has  not  overborne,  a  fruit  cane  may  be  left  from  one  of 
the  shoots  coming  from  the  lower  buds  of  the  fruit  cane  C,  and  a  new 
wood  spar  of  two  eyes  left  on  the  shoot  coming  from  the  wood 
spur  of  the  previous  year  (W).  In  this  case,  the  removal  of  the  arm 
at  K  is  deferred  one  year,  and  the  extra  vigor  of  the  vine  is  made  use 
of  to  produce  an  extra  crop. 

Type  III. — This  style  is  an  ex- 
tension of  the  principles  used  in 
type  II,  as  will  be  understood  by 
referring  to  Fig.  VI.  The  fruiting 
canes  are  left  still  longer,  and  in 
some  cases  almost  the  full  length  of 
the  cane.  As  each  cane  will  thus 
produce  a  large  amount  of  fruit, 
fewer  arms  are  necessary  than  in 
the  preceding  method.  It  is  es- 
pecially necessary  to  leave  good, 
strong  spurs  of  one  or  two  eyes  to 
produce  wood  for  the  following 
year.  There  are  various  methods 
of  disposing  of  the  long  fruiting  canes,  the  worst  of  which  is  to  tie 
them  straight  up  to  the  stake,  as  was  recommended  for  the  half-long 
canes.  In  the  latter  case,  owing  to  their  shortness,  ,a  certain  amount 
of  bending  of  the  canes  is  possible  with  this  method  of  tying.  With 
long  canes,  on  the  contrary,  it  usually  allows  of  no  bending,  and  as 
a  result  there  ensues  a  vigorous  growth  of  shoots  at  the  ends  of  the 
fruiting  canes,  and  little  or  no  growth  in  the  parts  where  it  is  necessary 
to  look  for  wood  for  the  following  year.  Often,  indeed,  each  long 
cane  will  produce  only  three  shoots  and  these  from  the  three  terminal 
eyes,  all  the  other  eyes  of  the  cane  remaining  dormant.  The  object 
of  long  pruning  is  thus  doubly  defeated,  ist  because  no  more  shoots 


II 


are  produced  than  by  short  pruning,  and  2nd,  because  the  shoots 
which  should  produce  fruit  are  rendered  especially  vigorous  by  their 
terminal  and  vertical  position,  and  therefore  less  fruitful.  Each  year 
all  this  vigorous  growth  of  wood  at  the  ends  of  the  canes  must  be  cut 
away  in  order  to  keep  the  vine  within  practical  bounds,  and  the  fruit 
canes  renewed  from  the  less  vigorous  cane  below.  These  canes  ate 
less  vigorous  because  the  main  strength  of  the  vine  has  been  ex- 
pended on  the  upper  canes  which  are  most  favorably  placed  for  vege- 
tative vigor.  Vines  treated  in  this  way  may  be  gradually  exhausted 
though  producing  only  a  moderate  or  small  crop  of  fruit,  by  being 
forced  to  produce  an  abundant  crop  of  wood. 

One  of  the  simplest  ways  of 
tying  the  fruiting  canes  is  illus- 
trated by  Fig.  VII.  The  canes  are 
bent  into  a  circle,  the  ends  tied  to 
the  stake  near  the  head  of  the  vine, 
and  the  middle  of  the  circle  at- 
tached higher  up.  The  tying 
should  be  done  so  that  the  cane 
receives  a  severe  bend  near  the 
base — that  is  about  the  region  of 
the  second  and  third  eyes.  This 
can  usually  .be  accomplished  by  ty- 
ing the  end  of  the  cane  first,  and 
then  pressing  down  on  the  middle 
of  the  bow  until , the  desired  bend  is  attained.  If  two  fruiting  canes 
are  left,  they  should  be  made  to  cross  each  .other  at  right  angles  in 
order  to  distribute  the  fruit  as  equally  as  possible.  As  a  rule  more 
than  two  canes  should  not  be  tied  up  in  this  way  as  it  makes  too  dense 
a  shade  and  masses  the  fruit  too  much. 


Fig.  VIII  shows  another  method  of  tying  the  long  canes.  A 
horizontal  wire  is  stretched  along  the  row  at  about  fifteen  to  twenty 
inches  above  the  ground.  To  this  the  fruiting  canes  should  be  at- 
tached, using  the  same  precaution  of  bending  the  canes  near  the  bases. 
The  upper  part  of  the  canes  is  not  bent  in  this  case  as  in  the  last,  but 
the  necessary  diminution  of  vigor  and  increase  of  fruitfulness  is 
brought  about  by  the  horizontal  position.  Two  canes  may  be  attached 
to  the  wire  on  each  side.  The  stake  is  best  used  to  support  the 


12 


shoots  destined  for  the  wood  for  the  following  year.  This  makes  it 
possible,  where  topping  is  practiced,  to  cut  off  the  ends  of  the 
shoots  from  the  fruiting  canes  and  to  leave  the  rest  their  full  length. 
Another  or  even  two  other  wires  may  be  used  above  the  first  for 
more  canes,  but  this  is  seldom  profitable,  and  considerably  increases 
the  cost  both  of  installation  and  or  pruning. 

This  style  of  pruning  is  especially  favorable  to  varieties  of  small 
growth  which  bear  small  bunches  and  principally  on  the  upper  eyes, 
and  to  varieties  of  larger  growth  in  hilly  or  poor  soils.  One  of  its 
main  objections  is  that  it  renders  some  varieties  more  liable  to  sun- 
burn. 

It  will  be  noticed  that  the  long-pruned  vines  are  represented  in  the 
figures  as  having  much  fewer  arms  than  the  short-pruned.  This  is 
necessary  and  important.  In  order  to  maintain  a  well-balanced  vine 
and  keep  it  under  control,  there  should  be  only  about  as  many  arms 
as  long  canes,  or  at  most  one, or  two  more. 

Types  IV,  V  and  VI. — The  .three  styles  of  pruning  so  far  de- 
scribed have  been  fairly  thoroughly  tested  in  .California,  and  each  has 
been  found  applicable  to  certain  varieties  and  conditions.  There  are 
some  varieties,  however,  which  do  not  give  good  results  with  any  of 
these  systems.  This  is  the  case  with  many  valuable  table  grapes,  es- 
pecially when  grown  in  rich  valley  soil,  where  they  should  do  best. 
For  these  cases  some  modification  of  the  French  cordon  system  is  to 
be  recommended.  Little  trial  of  this  method  has  been  made  as  yet, 
but  what  has  been  done  is  very  promising.  The  tendency  of  many 
grapes  to  coulure  is  overcome,  and  rich  soils  are  made  to  produce  crops 
in  proportion  to  their  richness.  The  method  consists  essentially  in 
allowing  the  vine  to  grow  in  a  more  or  less  horizontal  direction  for 
several  feet,  thus  giving  a  larger  body  and  fruiting  surface. 

The  treatment  of  the  young  vines  the  first  year  is  the  same  as  for 


head  pruning,  as  already  described.  As  soon  as  the  young  vine  pro- 
duces a  good,  strong  shoot  it  is  tied  up  to  the  wire  and  to  the  stake 
which  is  placed  between  the  vines  in  the  rows.  Each  vine  should 
finally  reach,  its  neighbor,  but  it  requires  two  or  three  years  for  this 
if  the  vines  are  six  or  seven  feet  apart  in  the  rows.  It  is  possible  by 
cutting  the  vine  back  nearly  to  the  ground  for  the  first  year  or  two 
to  obtain  a  cane  which  will  stretch  the  whole  distance  between  the 
vines  at  the  first  tying  up;  but  this  is  not  necessary  nor  advisable. 
Neither  is  it  advisable  to  make  a  very  sharp  angle  (almost  a  right 
angle)  as  is  usually  done  in  regular  cordon  pruning,  on  account  of 


13 

the  difficulty  of  preventing  the  vine  from  sending  out  an  inconvenient 
number  of  shoots  at  the  bend.  The  vine  might  be  grown  with  two 
branches,  one  stretching  in  either  direction,  but  this  has  been  found 
inconvenient  on  account  of  the  difficulty  of  preserving  an  equal  bal- 
ance of  the  branches.  The  direction  in  which  the  vine  is  trained 
should  be  that  of  the  prevailing  high  winds,  as  this  will  minimize 
the  chances  of  shoots  being  blown  off.  When  the  cordon  or  body  of 
the  vine  is  well-formed,  it  may  be  pruned  with  all  the  modifications  of 
short,  half-long  and  long  pruning  already  described  in  head  pruning, 
and  the  same  precautions  are  necessary  to  preserve  the  balance  and 
symmetry  of  the  vine  and  to  maintain  it  at  the  highest  degree  of  fruit- 
fulness  without  undulv  exhausting  it. 


Figs.  IX  and  X  will  sufficiently  illustrate  the  way  of  shaping  and 
tying  short  and  long-pruned  vines.  For  some  table  grapes  extension 
of  the  method  shown  in  Fig.  IX  in  the  direction  of  half-long  pruning 
is  useful.  On  a  heavy  soil  the  short  spurs  do  not  provide  sufficient 
outlet  for  the  vigor  of  the  vine,  while  long  pruning  would  unduly  in- 
crease the  number  of  bunches  on  a  single  cane,  and  so  reduce  their 
size,  which  would  deteriorate  from  their  value  as  table  grapes. 


Fig.  XI  represents  a  style  of  pruning  used  with  success  in  some 
of  the  richest  low-lying  soils  of  France.  The  body  of  the  vine  is  rais- 
ed up  to  a  height  of  two  and  a  half  or  three  feet  above  the  soil,  a  use- 
ful means  of  lessening  the  danger  from  spring  frosts.  The  fruit 
canes  are  bent  vertically  downward  thus  restricting  the  flow  of  sap 
sufficiently  to  force  out  the  lower  buds  of  the  fruit  canes  into  strong 
shoots  which  can  be  used  for  fruit  canes  of  the  follow- 


14 

ing  year.  This  does  away,  to  some  extent,  with  the  necessity  of 
leaving  wood  spurs,  and  much  simplifies  the  pruning.  Arms,  of 
course,  are  formed  in  time,  and  very  gradually  elongate,  so  that  it  is 
necessary  to  remove  one  occasionally  and  replace  it  by  a  water  sprout, 
as  already  explained  under  short  pruning. 

SUMMER  PRUNING. 

Some  form  of  summer  or  green  pruning  is  practiced  in  most  Cal- 
ifornia vineyards,  if  in  the  term  we  include  all  the  operations  to  which 
the  green  shoots  are  subjected.  There  seems,  however,  to  be  little  sys- 
tem used,  and  very  little  understanding  of  its  true  nature  and  object. 
In  general,  it  may  be  said  that  green  pruning  of  the  vine  is  least  need- 
ed and  often  harmful  in  warm,  dry  locations  and  seasons,  and  of 
most  use  under  cool  and  damp  conditions. 

The  principal  kinds  of  green  pruning  are:  I.  pinching;  2. 
suckering  and  sprouting;  3.  topping;  4.  removal  of  leaves. 

Pinching  consists  in  removing  the  extreme  growing  tip  of  a 
young  shoot.  It  is  necessary  to  remove  only  about  half  an  inch  to  ac- 
complish the  purpose  of  preventing  further  elongation  of  the  shoot  as 
all  growth  in  length  takes  place  at  the  extreme  tip.  The  immediate 
result  of  pinching  is  to  concentrate  the  sap  in  the  leaves  and  blos- 
soms, of  the  shoot,  and  finally  to  force  out  the  dormant  buds  in  the 
axils  of  the  leaves.  It  has  been  found  useful  in  some  cases  to  com- 
bat coulure  or  dropping  with  heavy-growing  varieties,  such  as  the 
Clairette  Blanche.  It  is  also, of  use  in  preventing  unsupported  shoots 
from  becoming  too  long  while  still  tender,  and  being  broken  off  by 
the  wind.  It  can,  of  course,  be  used  only  on  fruiting  shoots  and  not 
on  shoots  intended  for  wood  for  the  following  year. 

Suckerinq  is  the  removal  of  shoots  that  have  their  origin  below 
or  near  the  surface  of  the  ground.  The  shoots  should  be  removed  as 
thoroughly  as  possible,  the  enlargement  at  the  base  being  cut  off  in  or- 
der to  destroy  the  dormant  basal  buds.  An  abundant  growth  of  suckers 
indicates  either  careless  suckering  of  former  years,  (which  has  allowed 
a  mass  of  buds  below  the  ground,  a  kind  of  subterranean  arm,  to  de- 
velop, or  too  limited  an  outlet  for  the  sap.  The  latter  may  be  due  to 
frost  or  other  injuries  to  the  upper  part  of  the  vine,  but  is  commonly 
caused  'by  too  close  pruning. 

Sprouting  is  the  removal  of  sterile  shoots  or  "water-sprouts"  from 
the  upper  part  of  the  vine.  Under  nearly  all  circumstances  this  is  an 
unnecessary  and  often  a  harmful  operation,  especially  in  warm,  dry 
locations.  An  exception  may  perhaps  be  made  under  some  conditions 
of  varieties  like  the  Muscat  of  Alexandria,  which  has  a  strong  ten- 
dency to  produce  "water-sprouts"  which,  growing  through  the 
bunches,  injure  them  for  table  and  drying  purposes. 

Water-sprouts  are  produced  from  dormant  buds  in  the  old  wood, 
and  as  these  buds  require  a  higher  sap  pressure  to  cause  them  to 
start  than  do  the  fruitful  buds,  the  occurrence  of  many  water- 
sprouts  indicates  that  too  limited  a  number  of  fruitful  buds  has  been 
left  upon  the  vine  to  utilize  all  the  sap  pumped  up  by  the  roots.  To 
remove  these  water-sprouts,  therefore,  while  they  are  young  is  simply 
to  -shut  off  an  outlet  for  the  superabundant  sap  and  thus  to  injure  the 
vine  by  interfering  with  the  water  equilibrium,  or  to  cause  it  to  force 


15 

out  new  water-sprouts  in  other  places.  Any  vigorous  vine  will  pro- 
duce a  certain  number  of  water-sprouts,  but  they  should  not  be  looked 
upon  as  utterly  useless  and  harmful  because  they  produce  no  grapes. 
On  the  contrary,  if  not  too  numerous,  they  are  of  positive  advantage 
to  the  v^ne,  being  so  much  increase  to  the  feeding  surface  of  green 
leaves.  Water-sprouts  should  be  removed  completely  during  the  win- 
ter pruning,  and  the  production  of  too  many  the  next  year  prevented 
by  a  more  liberal  allowance  of  bearing  wood. 

Topping,  or  cutting  off  the  ends  of  shoots,  is  done  by  means  of  a 
sickle  or  long  knife.  At  least  two  or  three  leaves  should  be  left  be- 
yond the  last  bunch  of  grapes.  The  time  at  which  the  topping  is  done 
is  very  important.  When  the  object  is  simply  to  prevent  the  breaking 
of  the  heavy,  succulent  canes  of  some  varieties  by  the  wind,  or  to 
facilitate  cultivation,  it  must  of  course  be  done  early,  and  is  well  re- 
placed by  early  pinching.  These  objects  are,  however,  better  attained 
by  appropriate  methods  of  planting  and  training.  Early  topping  is  in- 
advisable because  it  induces  a  vigorous  growth  of  laterals  which  make 
too  dense  a  shade,  and  it  may  even  force  the  main  eyes  to  sprout,  and 
thus  injure  the  wood  for  the  next  year.  The  legitimate  function  of 
topping  is  to  direct  the  flow  of  food  material  in  the  vine  first  into  the 
fruit,  and  second  into  the  buds  for  the  growth  of  the  following  year. 
If  the  topping  is  done  while  the  vine  is  in  active  growth,  this  object  is 
not  attained;  one  growing  tip  is  simply  replaced  by  several.  In  this 
way,  in  rich,  moist  soils  vines  are  often,  by  repeated  toppings,  kept  in  a 
continual  state  of  production  of  new  shoots,  and  as  these  new  shoots 
consume  more  food  than  they  .produce,  the  crop  suffers.  Not  only 
does  the  crop  of  the  current  year  suffer,  but  still  more  the  crop  of  the 
following  year,  for  the  vine  devotes  its  energy  to  producing  new 
shoots  in  the  autumn  instead  of  storing  up  reserve  food-matrial  for 
the  next  spring  growth.  If,  on  the  other  hand,  the  topping  is  done 
after  all  leaf  growth  is  over  for  the  season,  the  only  effect  is  to  deprive 
the  vine  of  so  much  food-absorbing  surface. 

The  topping,  then,  should  be  so  timed  that,  while  a  further  length- 
ening of  the  main  shoot  is  prevented,  no  excessive  sprouting  of  new 
laterals  is  produced.  The  exact  time  differs  for  locality,  season  and 
variety,  and  must  be  left  to  the  experience  and  judgment  of  the  indi- 
vidual grower. 

Removal  of  leaves. — In  order  to  allow  the  sun  to  penetrate  to  and 
aid  the  ripening  of  late  grapes  it  is  often  advisable  late  in  the  season 
to  lessen  the  leafy  shade  of  the  vine.  This  should  be  done  by  remov- 
ing the  leaves  from  the  center  of  the  vines  and  not  by  cutting  away  the 
canes.  *  In  this  way  only  those  leaves  are  removed  which  are  injurious, 
and  as  much  leaf  surface  as  possible  is  left  to  perform  the  autumn  duty 
of  laying  up  food-material  for  the  spring.  The  removal  of  leaves 
should  not  be  excessive,  and  if  considerable,  should  be  gradual,  other- 
wise there  is  danger  of  sunburn.  It  is  best,  first,  to  remove  the  leaves 
from  below  the  fruit.  This  allows  free  circulation  of  the  air  and  pene- 
tration of  the  sun's  rays  which  warm  the  soil  and  are  reflected  upon 
the  fruit.  This  is  generally  sufficient,  and  in  any  case  only  the  leaves 
in  the  center  of  the  vine,  and  especially  those  which  are  beginning  to 
turn  yellow  should  be  removed. 


i6 

In  the  list  of  varieties  which  follows,  an  attempt  has  been  made  to 
indicate  the  mode  of  pruning  which  is  likely,  in  the  light  of  our  pres- 
ent knowledge,  to  give  the  best  results  for  each  variety.  It  should  be 
understood,  however,  that  it  is  to  some  extent  tentative  and  provis- 
ional. Many  of  the  varieties  have  proved  successful  in  certain  soils 
and  locations  when  pruned  in  the  way  indicated,  but  others  have 
never,  so  far  as  we  know,  been  tested  in  the  way  proposed.  As  these 
latter,  however,  have  proved  more  or  less  unsuccessful  under  the  com- 
mon methods  of  treatment  the  method  proposed  is  the  one  which 
seems  most  suitable  to  their  habit  and  general  characters.  It  seems 
probable  that  the  tendency  to  coulure  of  some  varieties  such  as  the 
Muscat,  Malbeek,  Merlot,  Clairette,  etc.,  can  be  combatted  to  a  great 
extent  by  appropriate  methods  of  pruning  and  training.  Unevenness 
of  ripening  and  liability  to  sunburn  of  Tokay,  Zinfandel,  etc.,  can 
doubtless  be  controlled  by  the  same  means. 

Very  few  varieties  succeed  under  strictly  short  pruning,  that  is 
cutting  back  to  one  and  two  eyes,  so  that  for  most  of  the  varieties  in 
the  first  category  the  modification  of  short  pruning  which  gives  fruit 
spurs  of  three  or  four  eyes  and  wood  spurs  of  one  eye  is  recommended. 

Type  I.  Charbono,  Cinsaut,  Mataro,  Carignane,  Grenache,  Petit 
and  Alicante  Bouschet,  Aramon,  Mourastel,  Verdal,  Ugni-blanc, 
Folle  blanche,  Burger,  Zinfandel,  Griiner  Velteliner,  Peverella,  Zier- 
fahndler  (?),  Rother  Steinschiller  (on  poor  soils),  Slankamenka,  Green 
Hungarian  (on  poor  soils),  Blue  Portuguese  (on  poor  soils),  Tinta 
Amarella,  Moscatello  fino,  Pedro  Ximenes,  Palomino,  Beba  (?),  Pe- 
runo,  Mantuo,  Mourisco  branco,  Malmsey,  Mourisco  preto,  Feher 
Szagos,  Muscat  of  Alexandria,  Sultanina,  Sultana,,  Barbarossa. 

Type  II.  St.  Macaire,  Beclan  (longer  or  shorter  according  to  rich- 
ness of  soil),  Teinturier  male,  Mon dense;  Marsanne,  Chasselas,  Mus- 
catel, Grosse  Blaue,  Sauvignon  blanc,/  Sauvignon  vert,  Nebbiolo, 
Fresa,  Aleatico. 

Type  III.  Cabernet  Sauvignon  and  Cabernet  Franc  (on  poor 
soils  and  hillsides),  Verdot,  Tannat,  Gamai  Teinturier,  Gros  Mansenc, 
Pinots,  Meunier,  Gamais,  Pinot  blanc,  Pinot  Chardonay,  Rul^nder, 
Afrenthaler,  Johannisberger,  Franken  Riesling  (on  hillsides),  Klein- 
berger,  Traminer,  Walschriesling,  Rothgipfler,  Lagrain  (?  perhaps 
short),  Marzemino,  Blue  Portuguese  (on  rich  soils),  Barbera,  Moret- 
to,  Refosco,  Tinta  de  Madeira,  Tinta  Cao,  Verdelho,  Boal.v<" 

Type  IV.  Green  Hungarian,  Rother  Steinschiller  (on  rich  soils), 
Neiretta,  Mission,  West's  Prolific,  Robin  noir. 

Type.V.  St.  Macaire  and  Mondeuse  (on  ricli  bottom  soils],  Tinta 
Valdepenas,  Marsanne,  Clairette  blanche,  Semillon,  Sauvignon  blanc 
(on  rich  soils),  Muscadelle  du  Bordelais,  Vernaccia  bianca,  Furmint 
Bakator,  Tadone,  Gros  Colman,  Black  Morocco  (?),  Cornichon  (?), 
Emperor,  Tokay  (?),  Almeria,  Pizzutello,  California  black  Malvoisie. 

Type  VI.  Malbec,  Petite  Strah  and  Serine,  Cabernet  Sauvignon 
and  Cabernet  Franc  (on  rich  bottom  soils),  Merlot,  Gros  Mansenc  (.? 
on  rich  bottom  soils),  Chauche  noir,  Bastardo,  Trousseau,  Ploussard, 
Etraie  de  TAdhui,  Chauchd  gris,  Franken  Riesling  (on  rich  soils). 


UNIVERSITY  OF  CALIFORNIA— COLLEGE  OF  AGRICULTURE, 

AGRICULTURAL  EXPERIMENT  STATION. 

E.  W.  HILGARD,  Director. 


REPORT  ON  CONDITION  OF  VINEYARDS  IN  PORTIONS 
OF  SANTA  CLARA  VALLEY. 


BY  FREDERIC  T.  BIOLETTI  AND  E.  H.  TWIGHT. 


DECAYED  TRUNK. 


(See  page  4.) 

BULLETIN    No.    134. 

(Berkeley,  Sept.  23,  1901.) 


SOUND  TRUNK. 


SACRAMENTO: 

A.  j.  JOHNSTON,  :::::::  SUPERINTENDENT  STATE  PRINTING. 

1901. 


UNIVERSITY  OF  CALIFORNIA, 

COLLEGE  OP  AaHICULTtmE,  AGRICULTURAL  EXPERIMENT  STATION. 

E.  W.  HILGABD,  DIRECTOR. 
BERKELEY,  CALIFORNIA. 


AUGUST  26,  1901. 
PROFESSOR  E.  W.  HILGARD, 

Director  of  Agricultural  Experiment  Station. 

DEAR  SIR:  In  accordance  with  your  directions  we  have  examined  the 
vineyards  of  Santa  Clara  with  the  object  of  determining  the  cause  of 
the  failure  and  death  of  a  large  number  of  vines  in  parts  of  that  county 
during  the  last  three  years.  It  is  not  possible  at  present  to  give  a  com- 
pletely satisfactory  explanation  for  such  serious  and  widespread  damage 
as  has  occurred,  but  our  observations  seem  to  prove  conclusively  two 
propositions:  First,  that  the  dying  vines  exhibit  symptoms  differing 
materially  from  those  shown  by  the  vines  in  Southern  California  which 
were  destroyed  by  the  Anaheim  disease;  and,  second,  that  whether  or 
not  there  be  some  u  unknown  influence  "  at  work,  as  suggested  by  Mr. 
Newton  B.  Pierce,  the  real,  determining  factor  is  the  deficiency  of  rain- 
fall during  the  years  1897-1900. 

Area  and  General  Character. — The  dying  of  vines  without  perceptible 
adequate  cause  during  the  last  three  years  has  by  no  means  been  con- 
fined to  the  west  side  of  the  Santa  Clara  Valley.  Similar  cases  have 
been  reported  and  investigated  over  a  wide  area  extending  from  the 
northern  part  of  Sonoma  County,  to  the  western  and  southern  parts  of 
the  Santa  Clara  Valley,  and  including  nearly  all  the  older  vineyard 
districts  within  these  limits.  The  only  peculiarity  of  the  cases  on  the 
west  side  of  the  Santa  Clara  Valley  is  their  number,  extending  in  many 
cases  to  every  vine  in  a  vineyard.  The  distribution  of  the  injured  and 
dead  vines  is  not  in  any  of  the  cases  examined  such  as  to  suggest  an 
infectious  parasitic  cause.  In  some  instances  single  vines  failed  and 
died  sporadically  where  the  main  bulk  of  the  vineyard  was  in  fair  con- 
dition, and  a  dead  vine  was  usually  surrounded  by  vines  which  were 
apparently  healthy. 

Nature  of  Injury. — In  most  of  these  sporadic  cases  examined  the  dying 
vine  was  found  to  have  been  severely  injured  in  some  way,  usually  by 
cutting  off  large  branches  at  the  pruning  and  thus  causing  large  wounds. 
Vines  of  this  kind  when  split  open  were  found  to  be  more  or  less 
decayed  in  the  middle,  and  many  were  quite  hollow.  In  a  report  made 
to  you  last  year  on  the  same  subject  this  decay  of  the  interior  of  the 
trunk  was  suggested  as  the  cause  of  death  in  some  cases.  This  year, 
however,  though  in  some  vineyards  the  hollow  vines  have  continued  to 


fail  and  die,  in  others  they  have  recovered.  This  indicates  that  though 
the  wood  decay  may  have  contributed  to  the  effect,  it  is  not  the  only, 
nor  indeed  the  chief  cause. 

The  accompanying  photograph  (plate  1)  illustrates  the  injury  done 
hy  the  cutting  off  of  a  large  branch. 

Note  in  the  subjoined  figure  the  large  wound  which  could  not  heal 
over,  and  which  allowed  a  large  amount  of  wood  to  dry  out.  Note  also 


PLATE  1.    VINE  INJURED  BY  HEAVY  PRUNING  WITHOUT 
PROTECTION  TO  WOUND. 

the  hole  made  by  a  boring  insect,  which  allowed  the  entrance  of  moisture 
and  of  white  ants,  and  thus  favored  the  growth  of  wood-rot  fungi.  The 
stem  of  this  vine  was  found,  on  being  split,  to  be  quite  hollow  nearly 
down  to  the  surface  of  the  ground.  For  the  general  appearance  of  vines 
of  this  kind  see  the  frontispiece,  which  is  taken  from  a  photograph  of 
one  of  the  vines  as  it  appeared  in  1900.  Note  the  contrast  with  the 
perfectly  healthy  appearance  of  the  neighboring  vine. 

Nature  of  Soil. — Nearly,  if  not  quite,  all  the  cases  occurred  in  grav- 
elly soil,  and  the  more  gravelly  the  soil  the  more  numerous  and  serious 


—  5  — 

the  cases.  Soil-borings  in  the  most  badly  affected  vineyards  showed  a 
layer  of  many  feet  of  coarse  gravel,  commencing  at  two  or  three  feet 
from  the  surface.  In  attempting  to  irrigate  in  these  places  the  growers 
had  much  difficulty  in  causing  the  water  to  flow  to  all  parts  of  the  vine- 
yard. A  large  stream  of  water  would  take  many  hours  in  passing  a 
few  yards,  on  account  of  the  extremely  leachy  nature  of  the  soil,  which 
allowed  the  water  to  escape  downward. 

Age  of  Vines. — It  is  to  be  noted  that  none  of  the  dying  vines  are 
young.  All  the  vineyards  examined  which  were  less  than  eight  years 
old  showed  no  indications  of  failing  or  dying.  All  cases  of  young  vines 


PLATE  2.    Two  HEALTHY  TROUSSEAU  VINES  IN  A  VINEYARD  OF  DEAD  MATARO  VINES. 

failing  which  were  examined  were  plainly  due  to  lack  of  cultivation, 
phylloxera,  sunburn,  or  other  well-known  and  adequate  causes. 

Another  fact  worth  mentioning  in  this  connection  is  that  old  vines 
which  were  grafted  just  before  the  three  dry  years,  are  now  nearly  or 
quite  healthy.  In  one  vineyard  a  block  of  old  Mataro  grafted  with 
Verdal  about  1896  shows  strong  growth  and  no  signs  of  failing,  while  a 
contiguous  block  of  the  same  variety  and  age,  but  un grafted,  is  prac- 
tically dead. 

Behavior  of  Different  Varieties. — A  great  deal  of  difference  was  every- 
where noted  in  the  behavior  of  different  varieties  of  vines.  The  most 
seriously  affected  were  Mataro,  Zinfandel,  Rose  of  Peru,  Mission, 
Emperor,  and  Burger.  Varieties  less  affected  were  Grenache,  Muscat, 


—  6  — 

and  Verdal.  These  three  varieties,  in  many  cases  where  they  looked 
very  bad  last  year  and  even  this  spring,  appear  to  be  recovering. 
Other  varieties  show  little  or  no  damage.  The  chief  of  these  noticed 
were  Trousseau,  Cabernet-Sauvignon,  Pinot  (?),  Verdot,  Robin  noir,  and 
Herbemont.  This  list  indicates  that  the  heaviest  bearers  are  the  most 
seriously  affected  and  that  all  the  immune  varieties  are  light  bearers. 
This  difference  in  varieties  was  so  marked  that  several  Trousseau  vines 
growing  in  a  Mataro  block  were  apparently  perfectly  healthy  and 
vigorous,  while  the  Mataro  were  all  dead.  This  is  shown  in  the  photo- 
graph (plate  2).  The  recovery  of  less  susceptible  varieties,  such  as 
Grenache,  was  in  several  cases  very  remarkable.  Two  adjacent  blocks, 
one  of  Grenache  and  the  other  of  Mataro,  showed  a  remarkable  contrast 


PLATE  3.    ADJACENT  BLOCKS  OF  MATARO  (DEAD)  AND  GRENACHE  (RECOVERING). 

when  examined  in  August  of  this  year.  Both  blocks  had  made  very 
short  growth  in  1900,  but  this  year  all  the  Mataro  were  dead,  while 
none,  so  far  as  could  be  seen,  of  the  Grenache  had  died,  and  though  the 
block  had  looked  sickly  in  the  spring,  when  examined  in  August  it 
showed  a  fine  growth  of  luxuriant  foliage  (see  plate  3). 

To  recapitulate;  the  main  facts  ascertained  are: 

1.  All  the  dying  vines  are  old. 

2.  All  the  serious  cases  are  in  gravelly  soil. 

3.  The  varieties  most  injured  are  all  heavy  bearers. 

4.  Vines  grafted  before  the  drought  are  healthy. 

5.  Vines  showing  serious  mechanical  injuries  succumb  first. 

6.  Vines  which  have  not  become  too  weak  appear  now  to  be  recov- 
ering. 


Causes. — These  facts  seem  to  indicate  that  we  can  ascribe  the  failure 
of  the  vines  to  a  general  cause  acting  over  the  whole  district;  a  cause, 
however,  which  was  only  effective  where  supplemented  by  one  or  more 
contributory  conditions.  These  conditions  are: 

1.  Excessively  gravelly  soil. 

2.  Susceptibility  of  the  variety  of  vine,  due  probably  to  heavy  bearing 
and  perhaps  to  some  peculiarity  of  wood  and  foliage,  or  roots. 

3.  Large  wounds  made  in  pruning. 

4.  Age  of  the  vine. 

5.  Severe  cutting  back  of  the  young  growth  by  spring  frosts. 

The  general  cause  seems  to  be  the  combined  effect  of  the  heavy  crops  of 
1896  and  1897  and  the  four  years  of  drought  which  followed. 

Rainfall  and  Crops. — The  following  statistical  table,  made  up  from 
data  furnished  by  the  Weather  Bureau  and  by  two  of  the  largest  vine- 
growers  in  the  most  seriously  affected  districts,  fortifies  the  above 
position : 

Relation  of  Precipitation  and  Irrigation  to  Crop,  in  Vineyards  in  Santa   Clara  Valley. 


Precipitation 
at  Santa  Clara. 

Crop  on  Vineyards  at  West  Side. 

Departure 
from  Normal 
Rainfall. 

A  (300  acres). 

B  (170  acres). 

1896                   

Inches. 
19.51 

11.82 
8.13 
15.56 
13.15 

Tons. 
1,413 

1,883 
500 
a  449 
6315 

Tons. 

dSQQ 
d215 
d  93 
c    94 

Inches. 
+3.24 

-4.45 
—8.14 
—  .71 
—3.12 

1897 

1898 

1899                     ..     ..  

1900 

a  Irrigated  35  acres. 

»>  Irrigated  300  acres. 

c  Irrigated  70  acres  in  February.  From  50  acres  of  the  irrigated  land  were  obtained 
49  tons  of  grapes,  and  from  the  remainder  of  the  vineyard  only  45  tons.  This  indicates 
about  1  ton  per  acre  on  the  irrigated  and  about  %  ton  per  acre  on  the  unirrigated 
portion. 

d  Estimated  from  the  wine  produced. 

If  the  figures  given  for  these  two  vineyards  are  typical,  which  there 
is  every  reason  to  suppose,  they  may  help  us  to  find  a  sufficient  cause 
for  the  death  of  the  vines  without  taking  refuge  behind  the  mysterious 
and  highly  unsatisfactory  Anaheim  disease.  In  1896  the  vines  bore  a 
large  crop,  but  were  supplied  with  sufficient  water  by  a  rainfall  of  three 
inches  above  the  normal.  They  therefore  entered  the  season  of  1897 
healthy,  but  probably  not  with  an  excess  of  reserve  food-material  laid 
up  in  the  stems  and  roots;  for  the  weakening  effect  which  a  heavy  crop 


often  has  upon  a  plant  is  due  to  the  fact  that  the  nutriment  which  it 
absorbs  and  assimilates  during  the  summer  and  autumn  is  nearly  all 
utilized  in  the  production  of  fruit,  and  little  is  stored  for  use  in  the  fol- 
lowing spring.  The  spring  growth  of  a  plant  is  all  due  to  this  reserve 
food,  and  is  the  weaker  the  less  of  this  reserve  it  has  to  draw  upon. 
Usually  a  year  of  heavy  bearing  is  followed  by  a  year  of  light  bearing, 
during  which  the  plant  is  able  to  recuperate  by  utilizing  the  food 
assimilated  during  that  year  for  building  up  its  vegetative  organs  and 
for  replenishing  its  depleted  reserve.  During  the  season  following  the 
heavy  crop  of  1896,  however,  the  weather  conditions  were  evidently  such 
as  to  force  the  vines  to  expend  all  their  resources  in  the  production  of 
the  phenomenally  large  crop  of  1897.  How  exceptionally  large  this 
crop  was  upon  the  vines  which  are  now  dying  is  not  quite  indicated  by 
the  table  above,  which  includes  the  crop  from  all  varieties  and  ages  of 
vines.  The  crop  on  the  old  vines  of  heavy-bearing  varieties  which  are 
now  dead  was  doubtless  much  in  excess  of  the  indicated  average.  At 
the  same  time  that  this  severe  drain  was  being  made  upon  them  there 
was  a  shortage  of  over  four  inches  in  the  annual  rainfall.  It  is  practi- 
cally certain,  therefore,  that  these  vines  were  obliged  to  start  the  year 
1898  with  empty  storehouses,  and  the  rainfall  of  that  year  being  just 
half  the  normal,  the  vines  not  only  bore  very  little,  but  were  unable  to 
obtain  nutriment  sufficient  to  satisfy  their  vegetative  needs  and  to  nour- 
ish their  permanent  organs — roots,  stems,  and  canes. 

The  next  year,  1899,  therefore,  they  commenced  to  fail  and  some  of 
them  to  die.  In  1900  still  more  died,  while  in  1901,  the  present  year, 
the  largest  mortality  of  all  occurred.  It  is,  perhaps,  not  quite  clear 
why  the  mortality  should  be  greatest  in  the  later  years  when  the  defi- 
ciency of  rain  was  less  than  in  1898,  the  year  of  the  greatest  drought. 
It  should  be  remembered,  however,  that  a  lack  of  water  may  affect  a 
plant  in  two  ways:  If  it  occurs  at  a  time  when  the  plant  is  in  vigorous 
growth  and  full  leaf  the  plant  is  injured  or  killed  by  diminution  of  the 
amount  of  water  in  its  cells  and  tissues,  due  to  the  excess  of  evaporation 
from  the  leaves  over  the  absorption  by  the  root  hairs.  In  this  case  the 
plant  dies  of  thirst  and  dies  suddenly  at  the  time  of  the  drought.  If 
there  is,  on  the  contrary,  a  chronic  deficiency  of  water  in  the  soil,  com- 
mencing in  the  winter  before  the  plant  commences  to  grow,  the  result 
is  simply  a  small,  weak  growth  of  foliage,  insufficient  to  supply  food  for 
the  needs  of  the  stem  and  roots.  The  roots  thus  having  a  restricted 
food-supply  fail  to  grow  with  normal  vigor  and  in  turn  fail  to  supply 
the  rest  of  the  plant  with  the  soil  nutrients  which  it  is  their  function  to 
collect.  We  have  in  this  latter  case  not  so  much  injury  from  thirst  as 
gradual  starvation,  which  is  slower  in  its  action  and  probably,  when 
several  dry  seasons  follow  each  other,  cumulative,  as  the  reserve  food- 
supply  becomes  each  year  more  depleted  until  the  plant  dies. 


Summary. — This,  then,  seems  to  us  the  true  explanation  of  the  death 
of  vines  in  the  Santa  Clara  Valley,  stated  in  a  few  words:  Slow  starva- 
tion, due  to  excessive  prolonged  drought  following  two  exceptionally  heavy 
crops.  That  some  vines  have  died  and  others  have  lived  is  due,  as  we 
have  shown,  to  cooperating  influences,  the  principal  of  which  are  the 
character  of  the  soil,  the  variety  of  grape,  the  age  of  the  vines,  and  the 
exhausting  effect  of  late  spring  frosts  in  certain  vineyards. 

The  objection  to  the  drought  theory  which  has  been  made,  that  irri- 
gated vines  have  suffered  as  much  as  unirrigated,  does  not  appear  to  be 
valid,  as,  in  all  the  cases  which  we  could  find,  the  irrigation  was  applied 
too  late.  Very  little  irrigation  was  practiced  until  1899,  and  then  only 
upon  the  worst  vineyards  where  the  vines  were  already  injured  beyond 
redemption.  The  irrigation  to  have  been  effective,  should  have  been 
given  during  the  winter  of  1897—98,  the  season  of  greatest  drought,  and 
immediately  succeeding  the  two  years  of  abnormally  heavy  crops. 
This  would  have  insured  the  strong  growth  of  foliage  during  the  fol- 
lowing summer  needed  to  repair  the  drain  of  the  preceding  years  and 
to  replenish  the  depleted  stores  of  reserve  food-supply  in  the  trunk  and 
branches.  That  irrigation  was  of  some  value,  even  when  practiced 
late,  is  indicated  by  the  record  of  vineyard  B  in  the  foregoing  table, 
which  shows  that  the  irrigated  portion  of  the  vineyard  produced  four 
times  the  crop  per  acre  produced  by  the  unirrigated  portion,  though 
the  amount  of  water  used  was  only  about  three  inches,  or  just  enough 
to  make  up  for  the  shortage  in  rainfall  of  the  year. 

Young  vs.  Old  Vines. — The  immunity  of  young  vines,  and  of  old  vines 
which  had  been  grafted  about  1897,  is  explicable  on  the  theory  that  they 
were  enabled  to  withstand  the  drought  because  they  did  not  bear  in  1897 
and  were  thus  saved  the  drain  of  that  heavy  crop.  The  same  reason  may 
account  to  some  extent  for  the  immunity  of  certain  light-bearing  varieties. 
That  vines  on  other  soils  and  in  other  localities  have  escaped  the  destruc- 
tion that  has  overtaken  the  West-side  vineyards  is  due  doubtless  to  the 
fact  that  the  three  destructive  factors  of  drought,  heavy  bearing,  and 
leachy  soil  have  not  elsewhere  been  so  great  nor  simultaneous. 

Not  Anaheim  Disease. — The  reasons  which  have  led  us  to  reject  as 
unproven  the  theory  which  ascribes  the  death  of  the  vines  to  the  Anaheim 
disease  are  based  upon  the  divergence  of  the  symptoms  from  those  which 
distinguish  that  disease  as  characterized  in  Bulletin  2  of  the  Division  of 
Vegetable  Pathology  of  the  U.  S.  Department  of  Agriculture,  entitled 
"  The  California  Vine  Disease,"  by  Newton  B.  Pierce.  This  pamphlet 
must  be  considered  as  the  highest  authority  on  this  disease,  as  it  is 
almost  the  only,  or  at  least  the  most  complete  and  voluminous,  publi- 
cation on  the  subject. 


—  10  — 

Characteristics  of  Anaheim  Characteristics  Shown  by  Dying  Vines 

Disease.  in  Santa  Clara  Valley. 


Mission  more  susceptible  than  Mataro 
or  Zinfandel. 


'Page 
141 


Mataro  and  Zinfandel  have  died  more 
generally  than  the  Mission. 


Vines  in  shade  of  trees   less   rapidly  i  j  Vines  near  trees  have  suffered  as  much 

affected.  108    |      or  more  than  others. 

j         ! 

Grafting  the  vines  does  not  save  them.  !    138    !  All  the  recently  grafted  vineyards  are 

healthy. 

Cuttings   from    affected    vines    which  |  I  There  are  many  instances  in  which  cut- 

show  the  disease  die  as  soon  as  the  j  tings  taken  during  the  last  two,  three, 

parent  vines.  I    152    i      and  four  years  from  Mataro  and  Mis- 

sion vines  which  are  now  dead  have 
been  planted,  or  grafted  on  phyllox- 
era-resistant stock,  and  have  now 
resulted  in  vigorous,  healthy  vines. 


Rotting    of    the    roots    is    a    constant  | 
symptom.  52 


Roots  of  most  of  the  injured  vines  are 
sound. 


*The  numbers  refer  to  pages  in  the  above-mentioned  bulletin. 

To  these  contrasts  should  be  added  the  apparent  recovery  of  Grenache 
vines,  which  were  badly  affected  last  year  and  this  spring,  but  which  in 
August  were  making  a  vigorous  healthy  growth.  Though  Mr.  Pierce 
may  not  make  the  statement  definitely,  the  impression  left,  on  reading 
his  publications  on  the  Anaheim  disease,  is  that  it  is  cumulative  and 
progressive  and  that  the  attacked  vines  never  recover. 

These  contrasts  prove  either  that  the  Anaheim  disease  is  not  the 
cause  of  the  death  of  the  Santa  Clara  vines,  or  that  the  characteri- 
zation of  the  disease  as  given  in  the  publication  above  referred  to  must 
be  profoundly  modified  to  include  the  symptoms  exhibited  by  these 
vines.  There  is,  however,  no  reason  at  present  to  suggest  the  Anaheim 
disease  if,  as  seems  at  least  very  probable,  the  causes  here  outlined  are 
sufficient  to  account  for  the  observed  effects. 

Practical  Lessons. — This  serious  disaster  contains  two  important  prac- 
tical lessons  to  horticulturists,  and  especially  to  vineyardists:  First, 
the  necessity  of  having  on  hand  the  means  for  supplementing  a  deficient 
rainfall,  even  in  what  are  usually  considered  the  non-irrigating  districts; 
and  second,  the  importance  of  choosing  varieties  adapted  to  special 
locations,  soils,  and  climates.  This  question  of  adaptation  is  particu- 
larly important  to  grape-growers  who  are  planting  phylloxera-resistant 
stock,  as  all  the  good  and  thoroughly  resistant  vines  are  comparatively 
limited  in  their  range  of  adaptability.  Wherever  new  vines  are  planted 
in  the  devastated  area  it  would  be  extremely  unwise  to  plant  any 
variety  which  has  not  well-proved  drought-resisting  qualities.  The 
resistant  vines  which  have  shown  the  best  results  so  far  on  the  west  side 
of  the  Santa  Clara  Valley  are  Rupestris  St.  George,  Rupestris  Martin, 
and  Champini.  The  last  has  thriven  almost  or  quite  as  well  as  the  two 


—  11  — 

Rupestris  varieties,  but  unless  it  shows  marked  superiority  in  some 
other  way  the  others  are  to  be  preferred  on  account  of  their  superior 
phylloxera-resistant  qualities  and  the  greater  ease  with  which  they 
root.  The  suggestion  that  Rupestris  St.  George  is  resistant  to  the 
Anaheim  disease  is  certainly  premature  when  based  upon  its  behavior 
in  the  Santa  Clara  Valley,  in  view  of  the  fact  that  the  presence  of  that 
disease  in  the  valley  is  more  than  doubtful,  for  even  Mr.  Pierce,  the 
acknowledged  authority  on  this  disease,  after  making  an  examination 
of  the  afflicted  vineyards,  says  in  the  "California  Fruit-Grower"  of 
July  27,  1901,  that  he  "will  not  express  an  opinion  at  this  time  as  to 
the  presence  or  absence  of  the  California  (Anaheim)  vine  disease  in  this 
district." 

FREDERIC  T.  BIOLETTI. 

E.  H.  TWIGHT. 


UNIVERSITY    OF    CALIFORNIA    PUBLICATIONS 

COLLEGE    OF  AGRICULTURE 
AGRICULTURAL  EXPERIMENT  STATION 


NEW  METHODS  OF  GRAFTING  AND  BUDDING  VINES 

BY  E.  H.  TWIGHT. 


1 

1 


HHC 


Riparia  Gloire  de  Montpellier. 
Rupestris  St.  George.  Solonis. 


BULLETIN     NO.   146 


BERKELEY:  THE  UNIVERSITY  PRESS 
November,  1902 


BENJAMIN  IDE  WHEELER,  Ph.D.,  LL.D.,  President  of  the  University. 

EXPERIMENT  STATION  STAFF. 

E.  W.  HILGARD,  Ph.D.,  LL.D.,  Director  and  Chemist. 

E.    J.    WICKSON,    M.A.,    Horticulturist,    and    Superintendent    of    Central    Station 

Grounds. 

W.  A.  SETCHELL,  Ph.D.,  Botanist. 
R.  H.  LOUGHRIDGE,  Ph.D.,  Agricultural  Geologist  and  Soil  Physicist.     (Soils  and 

Alkali.) 

C.  W.  WOODWORTH,  M.S.,  Entomologist. 

*M.  E.  JAFFA,  M.S.,  Assistant  Chemist.      (Foods,  Fertilizers.) 
G.  W.  SHAW,  M.A.,  Ph.D.,  Assistant  Chemist.      (Soils,  Beet-Sugar.) 
GEORGE  E.  COLBY,  M.S.,  Assistant  Chemist.     (Fruits,  Waters,  Insecticides.) 
LEROY  ANDERSON,  M.S. A.,  Animal  Industries,  San  Luis  Obispo. 
A.  R.  WARD,  B.S.A..  D.V.M.,  Veterinarian,  Bacteriologist. 
E.  H.  TWIGHT,  B.Sc.,  Diplome  E.A.M.,  Viticulturist. 
E.  W.  MAJOR,  B.Agr.,  Dairy  Husbandry. 
A.  V.  STUBENRAUCH,  M.S.,  Assistant  Horticulturist  and  Superintendent  of  Sub- 

*  stations. 

*J.  BURTT  DAVY,  Assistant  Botanist. 
H.  M.  HALL,  M.S.,  Assistant  Botanist. 

C.  A.  TRIEBEL,  Ph.G.,  Student  Assistant  in  Agricultural  Laboratory. 
C.  A.  COLMORE,  B.S,,  Clerk  to  the  Director. 


EMIL  KELLNER,  Foreman  of  Central  Station  Grounds. 
JOHN  TOUHY,  Patron, 


,    Tulare  Substation,  Tulare. 
JULIUS  FORRER,  Foreman,  j 

R.  C.  RUST,  Patron,  )    f 

>-  Foothill  Substation,  Jackson. 
JOHN  H.  BARBER,  Foreman,] 

S.  D.  MERK,  Patron,  )    . 

'     TT    ,  .  >  Coast  Range  Substation,  Paso  Robles. 

J.  H.  OOLEY,  Workman  in  charge,] 

S.  N.  ANDROUS,  Patron,)  (  Pomona. 

T    TTT    _..  _  >  Southern  California  Substation,   •<    _ 

J.  W.  MILLS,  Foreman,  ]  (  Ontario. 

V.  C.  RICHARDS,  Patron,          )    _ 

m    T     _  .  >  Forestry  Station,  Chico. 

T.  L.  BOHLENDER,  in  charge,] 

ROY  JONES,  Patron,       )    T 

TTT  n  •  r  Forestry  Station,  Santa  Monica. 

WM.  SHUTT,  Foreman, J 


*  Absent  on  leave. 


The  Station  publications  (REPORTS  AND  BULLETINS)  will  be  sent  to  any  citizen 
of  the  State  on  application,  so  long  as  available. 


NEW  METHODS  OF  GRAFTING  AND  BUDDING  APPLIED 

TO  THE  RE-ESTABLISHMENT  OF  VINEYARDS 

WITH   AMERICAN  VINES. 


When  two  branches  or  stems  of  closely  related  plants,  growing  side 
by  side  in  a  forest,  overlap  and  touch  each  other,  the  bark  becomes 
bruised  and  abraded.  In  such  cases  the  sap  exuding  from  the 
alburnum  frequently  produces  a  pad  or  callus  by  which  incorporation 
or  knitting  takes  place  and  the  parts  become  one.  From  this  obser- 
vation the  idea  of  creating  artificial  wounds  to  obtain  a  graft  probably 
originated. 

Grafting  above  ground  was  a  common  practice  in  the  vineyards  of 
the  Romans,  and  their  authors  describe  them  carefully,  while  they 
hardly  mention  the  underground  graft.  But  for  some  reason,  until 
recently  most  of  these  grafts  tried  upon  the  vines  in  modern  times 
have  failed.  In  the  last  ten  years  persistent  efforts  and  successful 
experimentation  in  Europe  have  brought  the  discovery  of  new  processes 
that  have  been  very  successful,  and  their  use  tends  to  become  widely 
spread,  though  a  few  years  ago  the  best  authorities  on  viticulture 
condemned  them. 

Green  Cleft  Graft. 

This  graft  is  used  a  great  deal  in  Hungary;  it  is  an  ordinary  cleft 
graft  made  on  the  green  shoots  of  very  young  vines.  The  shoot  used 
as  stock  is  cut  between  the  second  and  third  leaves  (A-A)  counting 
from  the  apex,  and  one  and  one-half  to  two  inches  above  the  third 
leaf.  The  latter  is  pinched  at  B-B.  The  scion  is  a  similar  shoot,  the 
leaves  of  which  are  pinched.  The  ligature  used  is  wool  or  raffia,  and 
must  be  removed  as  soon  as  it  begins  to  cramp  the  joint.  This  graft 
necessitates  the  decapitation  of  the  stock,  and  is  exposed  to  drying; 
and  though  used  successfully  on  some  vineyards  of  Hungary,  it  might 
not  do  as  well  in  our  drier  climate. 

Horwath  Graft. 

The  Horwath  graft  (Fig.  2)  consists  in  inserting  a  scion  bud  in 
the  place  of  an  eye  of  the  stock;  it  is  commonly  used  on  fruit  trees, 
but  the  excision  of  the  bud  on  a  vine  cannot  be  done  in  the  same  way, 
because  of  the  considerable  protuberance  existing  at  each  node.  The 
following  method  was  adopted  by  Horwath : 


4  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION, 


FIG.  1. 

GREEN    CLEFT    GRAFT. 


FIG.  2. 
HORWATH  GRAFT. 


NEW  METHODS  OF  GRAFTING  AND  BUDDING. 


5 


A  circular  incision,  penetrating  the  whole  depth  of  the  bark,  is 
made  £-inch  above  and  another  the  same  distance  below  the  bud  (a,  5) ; 
then  on  the  right  and  left  of  the  bud  two  longitudinal  parallel  incisions 
are  made,  joining  the  annular  incisions.  The  bud  thus  prepared  (c) 
should  be  placed  on  a  shoot  of  as  nearly  as  possible  the  same  diameter 
as  that  from  which  it  was  taken.  But  the  indispensable  point,  which 
marks  the  difference  between  ordinary  budding  and  Professor  Hor- 
wath's  method,  is  that  the  bud  must  be  placed  or  inserted  in  place  of 
another  bud  on  a  node. 

The  green  shoot  to  be  used  as  stock  having  been  chosen,  and  on 
the  latter  the  bud  where  the  graft  is  to  be  made  determined,  the  leaf 
on  that  node  is  removed  (c) .  Two  semi-annular  incisions  are  made 
(a  ,  &')  at  the  same  dis- 
tances as  on  the  scion,  and 
a  single  longitudinal  cut  is 
made  passing  through  the 
bark,  dividing  the  petiole  in 
two  and  joining  the  annu- 
lar incisions.  Then  with 
the  spatula  of  the  grafting 
knife  the  bark  is  lifted  on 
both  sides  so  as  to  form  two 
flaps,  as  in  ordinary  bud- 
ding. The  flaps  being  open , 
the  scion  is  inserted  (d) , 
the  flaps  brought  over  it 
and  the  joint  ligated.  A 
fortnight  or  twenty  days 
after,  this  is  cut  off.  This 
graft  has  given  good  results, 
but  is  a  lengthy  and  delicate 
operation . 

Salgues  Graft. 

The  Salgues graft  (Figs. 
3  and  4)  consists  of  fixing 
on  a  green  shoot  of  the  year 
an  elliptic  scion  or  shield 
carrying  a  bud  at  its  cen- 

Cl  I) 

ter.     It  is  budding,  but  so  FlG  3 

modified  as  to   be   cohsid-  SALGUES  GRAFT.     (Original.} 

ered  a  new  method;   the  grafts  obtained  are  perfect  and  the  joints 

invisible  except  for  a  slight  swelling. 


6  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT    STATION. 

On  any  internode  of  the  shoot  to  be  grafted  a  longitudinal  incision 
(Fig.  3,  a)  is  made  with  the  grafting  knife,  penetrating  the  whole 
depth  of  the  bark  and  about  the  length  of  the  shield;  with  the  haft  of 
the  grafting  knife  the  bark  is  raised  on  both  sides  of  the  slit;  the 
shoot  is  then  bent  inwards  and  the  lips  of  the  slit  open  easily  (Fig.  3,  &) . 
The  scion  bud  is  inserted  and  the  shoot  is  left  to  spring  up  into  its 
former  position.  The  scion  bud  is  then  compressed  by  the  bark,  and 
the  operation  is  completed  by  tying.  The  ligature  should  be  removed 
a  fortnight  or  twenty  days  afterwards. 


, 


a  b  c 

FIG.  4. 
SALGUES  GRAFT.     VIEWS  OF  SCION  BUD — («)  SIDE,  (&)  FRONT, 

(c)    BACK. 

In  order  that  the  Salgues  graft  may  be  a  success,  it  is  necessary, 
first,  that  the  stock  should  be  in  full  sap,  so  that  the  lips  of  the  slit 
may  be  easily  raised;  secondly,  that  the  scion  bud  should  be  carefully 
selected. 

When  a  green  shoot  is  cut  longitudinally  on  its  entire  length, 
different  colorations  may  be  noticed  along  the  section;  towards  the 
apex  the  shoot  has  not  yet  begun  to  lignify,  and  the  section  is  almost 
uniformly  green  in  color,  only  slightly  deeper  above  and  below  each 
node.  The  diaphragm  of  these  can  only  be  detected  at  the  second  or 


NEW  METHODS  OF  GRAFTING  AND  BUDDING. 


third  node  (counting  from  the  top)  by  a  slightly  lighter  color. 
Downwards  the  diaphragm  becomes  more  distinct;  finally,  still  lower, 
the  pith  begins  to  be  indicated  by  a  whitish  tint;  the  scion  bud  should 
be  taken  only  from  the  buds  in  which  the  diaphragm  is  already  well 
apparent,  but  on  the  part  of  the  shoot  where  the  white  pith  is  not 
noticeable.  Each  shoot  will  thus  give  two  or  three  good  eyes. 

In  practice,  when  one  tries  to  bend  a  young  vine- shoot  there  is  no 
resistance  at  the  top;  then  lower  down  it  resists,  and  still  lower  down 
it  does  not  bend  but  breaks.  When  the  fingers  can  easily  bend  the 
shoot  and  feel  a  slight  resistance,  one  is  sure  that  the  bud  in  that 
region,  together  with  the  one  above  and  the  one  below,  are  suitable 
for  budding.  It  is  necessary  to  tie  the  grafted  shoots  to  a  stake,  as 
they  are  thus  better  protected  and  do  not  dry  out  as  easily  as  when 
close  to  the  ground.  This  graft  is  simple,  gives  perfect  union,  and  is 
getting  to  be  very  generally  used.  It  is  of  great  value  in  reestablish- 
ing vineyards  on  resistant  stock. 

The  Salgues  graft  may  be  performed  on  mother  stocks  of  American 
vines  through  the  summer  as  shoots  develop;  one  can  bud  sixteen 
inches  apart  on  the  canes  with  the  object  of  obtaining  grafted  cut- 
tings for  the  next  season.  We  have 
seen  contracts  given  out  for  this  work 
for  $6  a  1000  knitted  grafts. 

Besson  Graft. 

As  stated  above,  the  Salgues 
scion-bud  is  grafted  on  the  internode 
of  the  shoot.  The  Besson  graft 
(Fig.  5)  like  that  of  Horwath,  is 
inserted  on  the  node  itself;  but  while 
the  method  of  the  Hungarian  viticult- 
urist  is  a  true  budding,  that  of  Besson 
is  an  inlaying. 

This  graft  is  made  in  spring,  at 
the  same  time  as  the  ordinary  bench 
graft.  A  special  pair  of  shears  is 
used,  with  curved  blades  perpen- 
dicular to  the  handle;  it  cuts  and 
lifts  the  bud,  the  same  operation 
being  made  on  the  stock  and  scion 
canes.  The  lateral  portion  detached  must  be  a  little  under  one-half  of 
the  thickness  of  the  shoot;  the  cut  is  regularly  curved  and  concave, 
and  about  one  inch  long. 


FIG.  5. 

BESSON    GRAFT. 

(Rev.  de  Fit.,  1894. 


8 


UNIVERSITY   OF   CALIFORNIA — EXPERIMENT    STATION. 


On  the  stock,  the  second  eye, counting  from  the  top  of  the  cutting, 
is  cut  out;  while  for  the  scion  any  one  of  the  eyes  on  the  cane  is  used. 
The  scion-bud  fits  perfectly,  as  it  is  the  same  blade  that  makes  the  two 
cuts.  The  cuttings  to  be  grafted  should  be  sixteen  inches  in  length 
their  top  being  limited  by  a  bud  cut  half-way  through.  The  graft  is 
tied  with  raffia,  as  in  other  bench  grafts.  So  far,  this  graft  tried  on 
green  shoots  has  not  been  a  success,  but  on  the  ripe  canes  the  results 
have  been  very  good  and  the  quality  of  the  knitting  is  specially  good. 

Clarac  Graft. 

In  the  Clarac  graft  (Figs.  6  and  7) ,  as  in  the  Besson  graft,  a  bud  is 
substituted  for  another  bud,  but  the  process  differs  in  many  points. 
To  prepare  the  stock  an  incision  is  made  an  eighth  of  an  inch  above  a 
bud  (Fig.  6,  a)  and  the  incision  is  continued  in  a  straight  section 
parallel  to  the  axis  of  the  cane,  penetrating  one-third  of  the  diameter; 
the  cut  is  stopped  when  the  length  is  a  little  over  the  width  of  the  blade 


FIG.  6. 
CLARAC  GRAFT. 

under  the  the  base  of  the  bud  (Fig.  6,  &).  The  blade  is  removed, 
laid  flat  on  the  cane  immediately  under  the  base  of  the  bud,  in  order 
to  indicate  by  the  width  of  the  blade  the  point  where  the  new  trans- 
verse and  oblique  incision  is  to  be  made,  to  prevent  the  first  section 
from  spreading  and  to  make  a  strong  notch  for  the  scion  to  rest 
upon  (Fig.  6,  c). 

The  scion-bud  is  obtained  in  the  same  way,  placed  on  the  stock  and 
tied. 


NEW  METHODS  OF  GRAFTING  AND  BUDDING. 

Another  way  of  making  the  Clarac  graft  consists  in  not  removing 
the  bud  on  the  stock,  only  the  longitudinal  cut  being  made.  The 
scion-bud  is  made  in  the  same  way  but  with  a  longer  bevel;  it  is 
inserted  in  the  slit  prepared  on  the  stock  and  tied.  The  bud  left  on 
the  stock  constitutes  a  sap  drawer,  which  facilitates  the  knitting  of  the 
scion -bud.  When  knitting  has  taken  place  the  stock  bud  is  removed. 


CLARAC  GRAFT:    METHOD  WHERE  BUD  IS  LEFT  ON  STOCK. 

(E.  de  Vit.,  1894.) 

The  second  method  is  more  rapid.  In  both  cases  the  ligature  must 
be  cut  away  three  weeks  after  being  made.  Both  methods  have  been 
successful. 


10 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 


Massabie  Graft. 

This  is  practically  the  same  as  the  Besson  graft,  but  the  scion-bud 
is  cut  with  a  special  pair  of  shears. 

Vouzou  Graft. 

The  Vouzou  graft  (Figs.  8  and  9)  is  a  Salgues  graft  made  with  an 

old  scion-bud.  On  a  smooth  part  of 
the  stock  above  ground  a  T-shaped 
incision  is  made  through  the  bark, 
and  the  sides  are  raised  with  the  haft 
of  the  grafting  knife. 

The  scion  is  taken  from  a  cane  of 
the  previous  year's  growth  before  the 
eyes  start  to  burst  in  the  spring,  and 
preserved  in  sand  until  the  time  of 
grafting.  The  bud  should  be  well 
constituted  and  healthy,  but  need  not 
be  at  a  particular  state  of  development, 
as  in  the  Salgues  graft.  The  scion- 
bud  is  cut  out  as  is  done  for  fruit 
trees,  but  under  the  eye  a  thickness  of 
wood  is  left  reaching  to  the  pith ;  and 
even  a  little  of  the  latter  may  be  left. 
This  will  give  a  scion  about  one  inch 
long,  with  the  inside  section  nearly 
flat.  The  bud  is  inserted  and  tied  in 
the  usual  way.  To  insure  knitting 
the  shoots  of  the  stock  must  be  pinched 
short;  the  tie  is  cut  one  month  after. 
This  graft  may  be  made  during 
the  whole  period  during  which  the 
sap  is  circulating,  and  when  the 
bark  is  detachable  from  the  wood. 
The  Vouzou  graft  has  been  very 
successful;  75  to  85  per  cent,  of 
"takes"  have  commonly  been  ob- 
tained, and  in  one  instance  the  suc- 
cess of  95  per  cent  was  publicly 
demonstrated.  It  is  a  simple  graft 

and  gives  a  perfect  union.     In  case  of  failure  it  is  easy  to  repeat  it 

the  same  season. 


FIG.  8. 

AN  ORDINARY  METHOD  OF  BUD- 
DING ON  A  VINE  CANE.  (a)  SLIT 
BEFORE  BUD  IS  INSERTED,  (&) 
SAME  AFTER  INSERTION  OF  SCION- 
BUD.  (Original.) 


NEW  METHODS  OF  GRAFTING  AND  BUDDING. 


11 


FIG.  9. 

SAME  AS  8  MAGNIFIED.    THE  TYING  OF  BUDS  HAS  BEEN  MADE 
WITHOUT  USING  THE  FOIL. 

(Rev.  de  Fit.,  1895.) 


MEANS   OF  INSURING  THE    SUCCESS   OF  HERBACEOUS   GRAFTS. 

Selection  of  shoots  bearing  buds  for  scions. — We  should,  always 
choose  branches  growing  from  eyes  which  would  have  normally 
remained  dormant  till  the  following  season,  in  preference  to  branches 
growing  from  buds  bursting  out  normally.  Shoots  of  medium  or 
rather  small  diameter  are  to  be  preferred.  These  shoots  will  furnish 
the  scion-buds  which  are  to  be  grafted  on  the  old  wood.  The  diameter 
of  the  shoot  from  which  the  scion-bud  is  cut  must  always  be  a  little 
smaller  than  the  diameter  of  those  upon  which  it  is  to  be  grafted. 
The  best  shoot  is  that  developed  in  the  shade;  branches  exposed  to 
direct  sunlight  must  always  be  rejected;  the  shoot  should  be  light 
green  in  color,  but  not  yellow. 

The  petioles  of  the  leaves  of  the  shoot  should  be  of  a  whitish-green 
color,  even  a  little  pinkish,  slightly  transparent  at  the  point  of  junc- 
tion with  the  limb.  Shoots  bearing  leaves  with  deep  green  or  reddish 
petioles  should  be  rejected.  The  eyes  of  the  extremity  and  base  of 
the  shoots,  together  with  those  placed  at  the  base  of  the  leaves  having 
a  very  slender  or  very  long  petiole  should  not  be  used. 


12 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 


Preparation  of  Scion-Buds. 

The  whole  of  the  petiole  and  part  of  the  limb  of  the  Jeaf  should  be 
left  when  the  leaf  is  pinched;  if  the  petiole  is  cut  shorter  the  bud 
dries  out.  The  same  bud  may  be  made  with  sap-wood  or  with  half 
sap-wood,  the  latter  is  by  far  the  best. 

Scion  with  Sap-wood.  —  (a,  &,  c,  Fig.  9;  «,  b,  c,  Fig.  4).  To  cut 
out  the  shields,  the  shoot  is  held  with  the  left  hand,  the  first  finger 
being  under  the  bud;  the  cut  is  begun  with  the  base  the  grafting 
knife  half  an  inch  below  the  bud;  and  while  cutting,  the  knife  blade 
is  drawn  in  such  a  way  that  the  end  of  the  grafting  knife  will  corre- 
spond with  the  end  of  the  section,  half  an  inch  below  the  bud,  when 
finished.  This  shield  will  be  about  li  inches  long,  and  as  it  will  have 
a  chipped  edge,  it  is  advisable  to  smooth  it  down,  which  will  reduce  it 
to  about  one  inch.  The  scion-bud  is  then  rather  thick  in  the  center 
and  the  ends  are  pointed  bevels.  The  sap-wood  of  the  shield  does  not 
knit,  therefore  it  is  advisable  to  diminish  its  surface. 

Scion  with  Half  Sap-wood. — This  is  far  superior  to  the  above.  The 
cut  is  started  in  the  same  way  (a,  Fig.  10),  but  the  knife  is  drawn 
parallel  to  the  axis  of  the  cane,  as  in  6,  Fig.  6.  Drawing  the  blade 
out  the  transversal  section  bb  (Fig.  10)  is  made  cutting  through  the 
bark  only. 

The  bud  is  seized  between  the  thumb  and  first  finger  of  the  right 
hand  and  lifted  (c)  and  pulled  back  (d) .  As  the  transverse  cut  only 


FIG.  10. 
PREPARING  A  HALF  SAP-WOOD  SCION -BUD. 

goes  through  the  bark,  in  lifting  the  bud  a  tongue  of  sap-wood 
remains  attached  to  the  cane  (d)  and  adheres  to  the  scion-bud.  When 
we  lift  this  up  it  breaks  off  level  with  the  bud,  leaving  a  two-pronged 
fork  (e,  Fig.  10).  If  the  fork  is  not  formed,  the  bud  should  be 


NEW  METHODS  OF  GRAFTING  AND  BUDDING.  13 

rejected,  as  it  is  not  ripe  enough.  It  is  hard  to  explain  this  mode  of 
operating,  but  it  is  really  easy  in  practice. 

Making  the  Slit  on  the  Stock. — On  one-  or  two-year-old  canes,  the 
slit  should  be  made  on  the  rounded  part  where  the  bark  is  thicker  and 
will  protect  better  against  desication.  However,  if  the  scion-bud  has 
a  little  sap-wood  attached,  it  is  better  to  place  it  on  the  flat  side.  On 
old  wood  the  bark  is  so  thin  that  it  is  almost  impossible  to  lift  it  off. 

Ligatures. — The  best  are  made  out  of  lead  or  tinfoil  tied  with  raffia 
or  cotton.  The  foil  is  cut  into  pieces  three-quarters  to  one  inch  wide 
and  two  to  three  inches  long. 

Arrangement  of  Mother  Stock. — All  shoots  of  American  stock  may 
be  readily  budded;  that  is  to  say  a  person  can  place  on  a  vigorous 
cane  from  ten  to  twenty  buds  and  obtain  the  next  season  from  one 
vigorous  mother  vine  100  to  150  grafted  cuttings.  Long  experience 
has  shown  that  to  obtain  these  results  it  is  necessary  to  arrange  the 
stocks  in  the  following  manner: 

Stakes  about  six  or  eight  feet  high  are  erected  ten  to  fifteen  feet 
apart.  As  soon  as  the  shoots  of  the  mother  stock  are  about  twenty 
inches  in  length,  eight  to  twelve  are  preserved  and  the  balance  dis- 
budded. The  shoots  are  tied  up  in  V-shape  as  soon  as  hard  enough, 
all  auxiliary  buds  and  tendrils  being  removed;  this  is  repeated  three 
times  in  the  season.  The  even  numbered  shoots  are  tied  up  on  one 
side  and  those  of  odd  numbers  on  the  other;  this  facilitates  the  bud- 
ding and  collecting  of  the  knitted  cuttings;  twice  the  amount  of 
wood  fit  to  be  budded  is  obtained  in  this  way.  On  an  experimental 
plot  one  hundred  4-year-old  Riparia  were  trellised  and  as  many  left 
without  trellising.  The  first  gave  an  average  of  175  feet,  the  latter 
75  feet  of  wood  suitable  for  budding. 

Gathering  and  Keeping  the  Budded  Cuttings. — We  should  wait  until 
the  leaves  have  fallen  off  before  gathering  the  cuttings;  they  should 
be  cut  off  on  the  spot;  the  whole  cane  should  not  be  cut  off  and 
then  the  cuttings  be  removed  later,  as  they  are  apt  to  be  bruised  if 
treated  thus.  As  the  cuttings  are  gathered,  the  eyes  of  the  stock  are 
removed,  excising  them  with  a  grafting  knife  as  closely  as  possible; 
those  where  the  buds  have  missed  may  be  kept  to  be  bench-grafted  the 
next  spring.  The  good  ones  are  placed  in  cases,  in  layers  separated 
by  fresh  moss  or  moist  straw.  A  lid  is  placed  on  the  box  and  the 
cases  are  placed  in  a  closed,  dry,  frost-proof  room,  and  kept  until 
planted.  Then  the  boxes  are  taken  out  to  the  nursery,  the  cuttings 
taken  out  one  by  one,  and  their  upper  end  freshened  with  a  grafting 
knife  (not  shears),  three-fourths  to  one  inch  being  removed  at  each 
end.  The  cut  end  is  then  coated  with  tar. 


UNIVERSITY  OF  CALIFORNIA  PUBLICATIONS. 


COLLEGE  OF  AGRICULTURE, 

AGRICULTURAL  EXPERIMENT  STATION. 


RESISTANT  VINES  AND  THEIR  HYBRIDS 


BY  E.  H.  TWIGHT. 


BULLETIN  No.  148. 

(Berkeley,  October,  1902.) 


SACRAMENTO: 

w.  w.  SHANNON,     :     :     :     :     SUPERINTENDENT  STATE  PRINTING, 

1903. 


BENJAMIN  IDE  WHEELER,  Ph.D.,  LL.D.,  President  of  the  University. 

EXPERIMENT  STATION  STAFF. 

E.  W.  HILGARD,  Ph.D.,  LL.D.,  Director  and  Chemist. 

E.  J.  WICKSON,  M.A.,  Horticulturist,  and  Superintendent  of  Central  Station  Grounds. 

W.  A.  SETCHELL,  Ph.D.,  Botanist. 

ELWOOD  MEAD,  M.S.,  C.E.,  Irrigation  Engineer . 

R.  H.  LOUGHRIDGE,  Ph.D.,  Agricultural  Geologist  and  Soil  Physicist.    (Soils  and  Alkali.) 

C.  W.  WOODWORTH,  M.S.,  Entomologist. 

M.JE.  JAFFA,  M.S.,  Assistant  Chemist.    (Foods,  Fertilizers.) 

G.  W.  SHAW,  M.A.,  Ph.D..  Assistant  Chemist.    (Soils,  Beet-Sugar.) 

RALPH  E.  SMITH,  B.S.,  Plant  Pathologist. 

GEORGE  E.  COLBY,  M.S.,  Assistant  Chemist.    (Fruits,  Waters,  Insecticides.) 

LEROY  ANDERSON,  M.S.A.,  Animal  Industries,  San  Luis  Obispo. 

A.  R.  WARD,  B.S.A.,  D.V.M.,  Veterinarian,  Bacteriologist. 

E.  H.  TWIGHT,  B.Sc.,  Diploma  E.A.M.,  Viticultunst. 

E.  W.  MAJOR,  B.Agr.,  Dairy  Husbandry. 

A.  V.  STUBENRAUCH,  M.S.,  Assistant  Horticulturist  and  Superintendent  of  Substations. 

WARREN  T.  CLARKE,  Assistant  Field  Entomologist. 

H.  M.  HALL,  M.S.,  Assistant  Botanist. 

C.  A.  TRIEBEL,  Ph.G.,  Student  Assistant  in  Agricultural  Laboratory. 

C.  A.  COLMORE,  B.S.,  Clerk  to  the  Director. 


EMIL  KELLNER,  Foreman  of  Central  Station  Grounds. 
JOHN  TUOHY,  Patron, 


.    Tulare  Substation,  Tulare. 
JULIUS  FOR  HER,  Foreman, 

R.  C.  RUST,  Patron,  ) 

J-  Foothill  Substation,  Jackson. 
JOHN  H.  BARBER,  Foreman,  ) 

S.  D.  MERK,  Patron,  ) 

>  Coast  Range  Substation,  Paso  Robles. 
J.  H.  OOLEY,  Workman  in  charge,  ) 

8.  N.  ANDROUS,  Patron,  )  (  Pomona, 

J-  Southern  California  Substation,   -\ 
J.  W.  MILLS,  Foreman,      )  (  Ontario. 

V.  C.  RICHARDS,  Patron,         ) 

V  Forestry  Station,  Chico. 
T.  L.  BOHLENDER,  in  charge,  ) 

ROY  JONES.  Patron,      ) 

}•  Forestry  Station,  Santa  Monica. 
WM.  SHUTT,  Foreman,  ) 


The  Station  publications  (REPORTS  AND  BULLETINS)  will  be  sent  to  any 
citizen  of  the  State  on  application,  so  long  as  available. 


RESISTANT  VINES  AND  THEIR  HYBRIDS. 


GENERALITIES  REGARDING  RESISTANT  VINES. 
(Abstract  from  Bulletin  No.  131,  by  F.  T.  Bioletti.) 

The  most  satisfactory  method  of  combating  phylloxera  is  the  use  of 
resistant  vines,  because  it  is  applicable  to  all  conditions  and  is  the  most 
economical  in  the  end.  A  resistant  vine  is  one  which  is  capable  of  keep- 
ing alive  and  growing  even  when  phylloxera  are  living  upon  its  roots. 
Its  resistance  depends  on  two  facts:  first,  that  the  insects  do  not  increase 
so  rapidly  on  its  roots;  and  second,  that  the  swellings  of  diseased  tissue 
caused  by  the  punctures  of  the  insects  do  not  extend  deeper  than  the 
bark  of  the  rootlets  and  are  sloughed  off  every  year,  leaving  the  roots 
as  healthy  as  before.  The  wild  vines  of  the  Mississippi  States  have 
evolved  in  company  with  the  phylloxera,  and  it  is  naturally  among 
these  that  we  find  the  most  resistant  forms.  No  vine  is  thoroughly 
resistant  in  the  sense  that  phylloxera  will  not  attack  it  at  all;  but  on 
the  most  resistant  the  damage  is  so  slight  as  to  be  imperceptible.  The 
European  vine  ( Vitis  vinifera,  L.)  is  the  most  susceptible  of  all,  and  all 
the  grapes  cultivated  in  California,  with  a  few  unimportant  exceptions, 
belong  to  this  species.  Between  these  two  extremes  we  find  all  degrees 
of  resistance,  which  is  expressed  by  a  series  of  numbers  ranging  from  20, 
indicating  the  highest  possible  resistance,  to  0,  indicating  the  utmost 
susceptibility.  The  following  table  shows  the  resistance  (according  to 
Viala  and  Ravaz  and  other  authorities)  of  some  of  the  best  known 
species  and  varieties: 

COMPARATIVE  RESISTANCE  TO  PHYLLOXERA. 

Species  (  Wild  Vines).  Cultivated  Varieties  and  Hybrids. 

Vitis  rotundifolia _.  19  Gloire  de  Montpellier  (Riparia).  18 

Vitis  vulpina  ( Riparia) 18           Riparia  X  Rupestris  3309 18 

Vitis  rupestris _ 18           Rupestris  Martin 18 

Vitis  Berlandieri _ 17           Rupestris  St.  George 16 

Vitis  sesti valis  .._ 16           Riparia  X  Solonis  1616 16 

Vitis  labrusca 5           Solonis. 14 

Vitis  Californica 4           Lenoir _ ..12 

Vitis  vinifera 0           Isabella.. ....J 5 

The  degree  of  resistance  necessary  for  the  production  of  good  crops 
varies  with  the  character  of  the  soil.  The  resistance  expressed  by  the 
numbers  16  to  20  is  sufficient  for  all  soils.  A  resistance  of  14  or  15  is 
sufficient  in  sandy  and  moist,  rich  soils,  where  the  vine  can  readily 
replace  the  rootlets  as  fast  as  they  are  destroyed.  Fairly  successful 
vineyards  have  been  established  exceptionally  with  vines  having  a 


4  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

resistance  of  less  than  14,  but  as  the  vines  become  old  the  lack  of 
resistance  is  generally  shown  by  a  weakening  of  the  vine  and  a  falling 
off  of  the  crop.  Many  vineyards  in  the  south  of  France  grafted  on 
Lenoir  which  formerly  bore  well,  have  now  to  be  doctored  with  injec- 
tions of  bisulfid.  For  this  reason  it  is  advisable  to  reject  all  vines 
with  a  resistance  of  13  or  under,  especially  as  v^ines  with  greater 
resistance  can  now  be  obtained  for  practically  all  conditions. 

Resistant  vines  are  of  two  kinds:  (a)  those  which  are  grown  for  the 
grapes  they  produce,  and  (b)  those  which  are  useful  only  as  stocks  on 
which  to  graft  the  non-resistant  varieties.  The  former  are  called 
"  direct  producers"  the  latter,  "  resistant  stocks." 

(a)  Direct  Producers. — When  the  phylloxera  commenced  to  destroy 
the  vineyards  of  Europe,  the  natural  attempt  was  made  to  replace  them 
with  the  varieties  of  vines  which  had  proved  successful  in  the  United 
States,  where  the  insect  was  endemic.  These  varieties,  however,  all 
proved  unsatisfactory.  Some,  like  the  Concord  and  the  Catawba,  were 
insufficiently  resistant,  and  although  they  could  be  grown  where  the 
severe  cold  of  winter  impeded  the  prolificness  of  the  phylloxera,  they 
quickly  succumbed  in  the  milder  grape-growing  sections  of  Europe.* 
Most  of  them  were  poor  bearers  compared  with  the  prolific  European 
vines,  and  finally  the  character  of  their  fruit  differed  so  widely  from 
what  Europeans  were  accustomed  to  that  there  was  little  sale  for  the 
fruit,  and  the  wine  could  compete  with  only  the  very  poorest  quality  of 
Vinifera  wines,  and  brought  a  very  inferior  price.  A  few  of  the  varieties 
introduced  during  that  first  period  are  still  grown  to  a  limited  extent  in 
France,  chiefly  the  Othello  and  the  Lenoir.  They  are  being  gradually 
abandoned,  however,  as  their  crops  are  unsatisfactory,  and  in  many 
localities  can  be  maintained  only  by  the  aid  of  injections  of  bisulfid. 
For  some  years  the  search  for  a  suitable  direct  producer  was  almost 
abandoned  by  practical  men,  the  use  of  resistant  stocks  having  been  so 
fully  successful.  Lately,  however,  renewed  efforts  have  been  made  and 
several  new  direct  producers  are  being  advocated  and  planted  to  some 
extent.  The  merit  of  these  new  varieties,  however,  is  chiefly  their 
resistance  to  Peronospora  and  Black  Rot.  Phylloxera-resistance  is  con- 
sidered of  much  less  importance  by  their  most  ardent  advocates,  and 
indeed  the  advice  is  given  to  graft  some  of  the  best  of  these  direct  pro- 
ducers upon  phylloxera-resistant  stock.  The  main  importance  of  these 
facts  to  California  grape-growers  is  that  they  hold  out  hopes  of  perma- 
nent prosperity  for  the  wine-making  industry  here,  where,  owing  to  the 
dryness  of  the  climate,  there  is  no  likelihood  of  trouble  from  these 
serious  fungous  diseases  of  the  grape,  which  threaten  to  make  the  grow- 
ing of  Vinifera  varieties  impossible  in  many  parts  of  Europe. 

*\n  California,  these  and  other  Labrusca  varieties  and  hybrids  resist  very  little  longer 
than  Vinifera  vines. 


I 


RESISTANT   VINES.  5 

(b)  Resistant  Stocks. — Though  high  resistance  to  phylloxera  is  essential 
in  a  grafting  stock,  there  are  other  characteristics  equally  necessary. 
The  Rotundifolia  (Scuppernong),  which  has  the  highest  resistance  of  any 
vine,  is  useless  as  a  stock  on  account  of  the  impossibility  of  grafting  it  with 
any  Vinifera  variety.  This  is  due  to  a  lack  of  affinity,  which  means  a 
lack  of  similarity  in  structure  and  composition  between  the  tissues  of  the 
stock  and  those  of  the  scion.  This  lack,  in  extreme  cases,  results  in  an 
imperfect  and  temporary  union,  but  when  not  excessive,  only  in  a  slight 
decrease  of  vigor.  The  affinity  is  not  perfect  between  Vinifera  varieties 
and  any  resistant  stock,  but  in  the  case  of  Riparia  and  Rupestris  is 
generally  sufficient  to  insure  permanence  to  the  union,  and  the  slight 
decrease  of  vigor  consequent  often  results  in  an  increase  of  fruitfulness. 
It  is  for  this  reason  that  certain  varieties  when  grafted  on  resistant  stocks, 
especially  on  Riparia,  often  bear  larger  crops  than  when  grown  on  their 
own  roots.  Not  all  varieties  of  Vinifera  have  the  same  affinity  for  the 
same  stock.  For  this  reason  it  is  desirable  to  be  cautious  about  making 
new  or  untried  grafting  combinations  on  a  large  scale.  Some  varieties, 
such  as  Carignan,  Petite  Sirah,  Clairette,  and  Cabernet  Sauvignon,  do 
excellently  on  all  stocks;  while  others,  such  as  Mondeuse  and  Gam  ay, 
do  not  make  a  very  good  union  with  any  of  the  thoroughly  resistant 
stocks.  The  Petit  Bouschet  and  Cinsaut  make  very  poor  unions  with 
any  variety  of  Riparia,  but  do  fairly  well  on  Rupestris  St.  George.  The 
Pinot  Noir  makes  a  vigorous  growth  upon  Rupestris  St.  George,  but 
bears  much  more  prolifically  upon  Riparia  Gloire. 

Selection. — A  very  serious  defect  of  many  resistant  stocks  is  a  slender 
habit  of  growth.  This  is  true  of  most  of  the  vines  found  growing  wild, 
and  cuttings  from  such  vines  make  poor  grafting  stock  for  the  stout 
Vinifera  varieties,  which  will  produce  a  trunk  four  inches  in  diameter 
while  the  stock  is  growing  only  two  inches.  This  is  particularly  true 
of  the  wild  Riparias.  For  this  reason  great  care  has  been  exercised  in 
selecting  the  stronger-growing  forms,  and  at  present  we  have  selected 
Riparia  varieties  which  almost  equal  Vinifera  in  the  stoutness  of  their 
trunks.  The  best  of  these  are  the  Riparia  Gloire  de  Montpellier  and 
the  Riparia  Grande  Glabre,  the  first  of  which  has  given  the  best  results 
in  California. 

RESISTANT  VINES  AND  THEIR  HYBRIDS. 

BY  E.  H.  TWIGHT. 

If  we  study  the  conditions  affecting  the  adaptation  of  resistant  vines, 
we  see  that  the  amount  of  lime  contained  in  the  soil,  the  degree  of  com- 
pactness, the  moisture,  and  the  fertility  of  the  land  are  the  most 
important  factors.  The  proportion  of  lime  in  the  soil  has  been,  in 
many  countries  and  particularly  in  France,  the  greatest  drawback  in 


6  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT   STATION. 

re-establishing  vineyards  on  resistant  stock.  Happily,  in  California  we 
do  not  have  to  contend  with  that  part  of  the  problem,  as  few  soils  con- 
tain enough  lime  to  affect  even  the  Riparias  and  Rupestris,  that  are 
among  the  first  to  suffer  from  excess  of  carbonate  of  lime. 

The  compactness  of  the  soil,  generally  due  to  the  large  proportion  of 
clay  it  contains,  is  an  obstacle  to  the  good  growth  of  many  varieties  of 
resistant  stock;  the  roots  do  not  penetrate  easily,  the  ground  is  cold 
and  often  wet,  and  under  such  conditions  the  Rupestris  and  Riparia, 
for  instance,  do  poorly.  On  the  contrary,  the  Lenoir,  Champini, 
Riparia  X  Rupestris  No.  3306  and  10114  will  do  well  in  such  locations, 
and  the  hybrids  of  Solonis  X  Cordifolia  X  Rupestris  will  do  still  better. 
The  last-mentioned  have  a  higher  resistance  to  phylloxera  than  Lenoir 
and  Champini.  If  we  examine  the  probable  cause  for  the  special 
adaptation  to  heavy  soils,  we  see  that  whereas  the  Riparia  and  Rupes- 
tris have  light,  thin,  hard  roots  very  much  ramified;  on  the  contrary 
the  varieties  adapted  to  such  soils  have  strong,  fleshy  roots,  less 
ramified,  with  a  heavier  hair  system  on  the  rootlets. 

When  in  excess,  the  moisture  in  the  soil  affects  the  vine  by  checking 
the  growth  of  the  root  system.  Plants  growing  in  a  very  moist  place 
may  have  a  vigorous  aerial  growth,  but  the  root  system  is  generally 
weak;  such  a  plant  will  suffer  greatly  if  for  some  reason  the  supply  of 
moisture  should  fall  below  the  average.  The  root  system  in  a  dry 
exposure  will  always  be  much  more  vigorous,  as  the  plant  has  to  send 
its  roots  lower  down  to  find  the  water  it  needs.  On  the  other  hand,  a 
moist  soil  will  help  a  vine  in  its  fight  against  phylloxera,  and  under 
such  conditions  some  stocks,  though  inferior  in  absolute  resistance,  may 
do  fairly  well.  As  a  general  rule,  the  Solonis  and  its  hybrids  are  very 
good  in  wet  soils. 

The  fertility  of  the  soil  is  a  condition  of  adaptation  that  we  must  not 
overlook:  A  Riparia  or  a  Solonis  will  turn  yellow  and  look  sick  in  a  soil 
where  a  Rupestris  would  do  fairly  well.  This  does  not  mean  that  a 
Rupestris  will  not  do  better  in  a  good  soil  than  in  a  poor  one,  but  simply 
that  it  is  more  rustic  in  its  adaptation. 

VARIETIES   OF    RESISTANT    STOCK. 

We  give  below  the  adaptation  of  the  principal  varieties  of  resistant 
vines  used  as  grafting  stock  or  as  parents  in  the  making  of  hybrids. 
(Riparia,  Rupestris,  Candicans,  Cordifolia,  Monticola,  Arizonica,  Cali- 
fornica,  Berlandieri.) 

Vitis  riparia. — The  V.  riparia  (see  title-page)  is  very  resistant  to 
phylloxera  (18).*  The  grafts  made  on  this  stock  are  fructiferous, 
vigorous,  and  advanced  in  maturity.  All  varieties  root  readily  from 

*Resistance  to  the  phylloxera  is  indicated  by  figures  on  the  scale  of  20  points. 


RESISTANT    VINES.  7 

cuttings  and  from  grafted  cuttings;  they  also  take  easily  from  field 
grafts.  This  stock  has  often  been  over-boomed,  and  planted  in  many 
localities  where  it  could  never  grow;  and  from  these  failures  some  people 
have  jumped  to  the  conclusion  that  the  stock  is  of  no  value.  But  when 
we  consider  that  in  France  alone,  seventy-two  per  cent  of  the  vineyards 
that  have  been  replanted  are  on  Riparia  roots,  we  readily  see  that  the 
failures  must  be  due  to  the  ignorance  of  the  conditions  of  adaptation. 
Riparias  do  not  grow  well  in  dry  locations;  they  must  have  a  good 
loamy  soil,  the  best  being  clayey-siliceous  alluvions;  a  deep,  cool,  fertile 


PLATE  1.    VITIS  RUPESTRIS  ST.  GEORGE. 

Showing  on  the  right  the  natural  fold  of  the  leaves  along  the  mid  rib,  and  on  the 
left  the  bracket-shaped  petiolar  sinus. 

soil,  not  too  wet.     The  two  varieties  mostly  used  are  the  Riparia  Gloire 
de  Montpellier  and  the  Riparia  Grande  Glabre. 

Vitis  rupestris. — This  vine,  shown  in  Plate  1 ,  is  found  in  its  wild  state 
in  open  places  along  hillsides  and  ravines  in  the  arid  eastern  part  of  the 
region,  growing  in  gravels  and  in  decomposed  rocks.  From  this  natural 


8 


UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 


habitat  we  may  see  that  it  will  be  well  adapted  to  light  gravelly  soil?, 
hillsides,  and  sandy  soils.  It  is  very  resistant  to  phylloxera  (16-18). 
The  Rupestris  vines  have  a  larger  trunk  than  the  Riparias  and  show, 
after  grafting,  less  difference  between  the  scion  and  stock.  The  cuttings 
root  easily,  but  not  quite  as  well  as  those  of  Riparias;  the  rooting  can 
be  aided  by  scratching  the  bark  of  the  lower  part  of  the  cutting  on  a 
short-tooth  iron  comb.  The  returns  in  bench-grafting  are  about  the 
same  as  those  obtained  with  Riparia.  As  the  Rupestris  cuttings  sucker 
very  much,  it  is  of  great  importance  to  suppress  carefully  the  eyes  on 


PLATE  2.    VITIS  CANDICANS.    MUSTANG  GRAPE. 

Showing  the  entire  or  lobed  leaves  with  the  limb  convex  on  the  upper  face. 
Three  of  the  leaves  are  turned  over,  showing  the  very  thick,  white  felt 
on  the  under  face  of  the  leaves. 

the  stock  when  bench-grafting.  Of  the  two  varieties  that  are  mostly 
used,  the  Rupestris  Martin  is  possibly  a  little  better  adapted  to  dry 
locations.  The  Rupestris  St.  George,  though  well  adapted  to  gravelly 
hillsides  and  light  soils,  has  proved  also,  in  the  last  few  years,  to  be  a 
vigorous  grower,  even  in  lands  where  the  water-table  is  close  to  the 
surface  several  months  in  the  year.  (Letter  from  Prof.  L.  Ravaz.) 

Vitis  candicans. — The  V.  candicans,  or  Mustang  grape  (Plate  2),  found 
in  its  wild  state  in  Texas  and  Arkansas,  grows  generally  on  bottom 


RESISTANT   VINES. 


9 


lands  and  along  rivers,  but  it  is  also  found  in  very  dry  locations;  in 
these,  however,  its  growth  is  not  as  vigorous.  It  does  best  in  alluvial 
soils,  but  its  large  roots  enable  it  to  grow  well  in  heavy  clays.  This 
variety  is  hard  to  grow  from  cuttings,  but  is  very  valuable  in 
hybridization. 

Vitis  cordifolia. — This  vine  is  adapted  to  the  same  class  of  soils  as 
the  V.  riparia;  it  is  very  highly  resistant  to  phylloxera,  and  does  fairly 
well  in  heavy  soils;  it  has  been  also  used  to  great  advantage  in  creating 
hybrids. 


PLATE  3.    V.  ARIZONICA. 

Vitis  arizonica. — This  vine  (Plate  3)  is  found  mostly  in  Arizona  and 
New  Mexico,  while  numerous  hybrids  of  Arizonica  X  Californica  exist 
in  the  region  where  both  varieties  grow  wild.  It  grows  well  from 
cuttings,  is  nearly  as  resistant  as  Rupestris,  and  ought  to  be  studied 
carefully.  In  adaptation  it  would  hold  a  place  between  the  Riparia 
and  the  Rupestris. 


10  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

Vitis  monticola. — This  vine  has  only  a  limited  range  of  distribution 
in  Texas,  where  it  is  found  on  lands  similar  to  those  where  the  Rupes- 
tris  grows,  but  containing  generally  a  high  percentage  of  lime.  It  comes 
next  to  the  Berlandieri  as  a  resistant  to  chlorose,  which  is  caused  by 
excess  of  lime  in  the  soil.  This  stock  is  a  very  good  element  in  hybrid- 
izing, and  may  turn  out  to  be  very  valuable  as  a  direct  grafting  stock. 

Vitis  calif ornica. — The  wild  native  vine  of  California;  it  has  a  resistance 
to  phylloxera  too  low  to  be  of  much  use. 

Vitis  Berlandieri. — This  vine  is  found  in  Texas,  New  Mexico,  and 
Mexico,  growing  on  limestone  ridges,  where  it  resists  excessive  drought 
and  heat.  The  quality  of  resistance  to  lime  would  not  be  of  much  interest 
in  California,  but  it  may  prove  to  be  a  very  valuable  stock  in  heavy, 
dry  soils,  as  probably  its  large  fleshy  roots  will  allow  it  to  penetrate 
readily.  Though  the  Berlandieri  does  not  grow  well  from  cuttings,  its 
hybrids  have  not  that  drawback. 

From  these  few  remarks  on  the  principal  resistant  stocks  we  may  see 
that  the  range  of  adaptation  of  each  variety  is  rather  narrow.  This 
observation  led  the  nurserymen  and  the  experiment  stations  in  the 
countries  mostly  interested,  to  try  to  obtain,  by  hybridizing,  new 
varieties  having  a  wider  range  of  adaptation.  This  has  been  done  with 
two  different  objects  in  view.  Some  simply  crossed  the  American 
resistant  varieties  to  obtain  new  grafting  stocks  having  a  larger  range 
of  adaptation;  we  will  call  these  Americo  X  American  hybrids.  Others 
tried  to  cross  the  American  resistant  stocks  with  the  Vinifera-producing 
varieties,  to  obtain  a  resistant  direct  producer;  we  will  call  these 
Vinifera  X  Americans.  So  far  the  latter  have  only  succeeded  in  making 
some  good  grafting  stocks,  the  bearing  qualities  of  the  Vinifera  not 
being  transmitted. 

AMERIGO  X  AMERICAN  HYBRIDS. 

Mr.  Munson,  in  the  United  States,  and  a  great  number  of  scientists  in 
Europe  (Couderc,  Millardet,  Grasset,  Foex,  Ravaz)  have  created  a 
large  number  of  new  hybrids,  some  of  the  most  promising  of  which  we 
will  review. 

Riparia  X  Rupestris. — This  group  is  probably  one  of  the  most  inter- 
esting. Among  the  varieties  selected  as  the  best  at  present  we  find 
NOB.  3306  and  3309  of  Couderc  and  No.  101U  of  Millardet.  They  are 
very  resistant  to  phylloxera,  root  easily  from  cuttings,  and  give  a  high 
percentage  of  good  grafts.  The  trunk  increases  rapidly  in  size,  so  that 
there  is  little  difference  between  stock  and  scion;  the  fructification  after 
grafting  is  good  and  regular.  The  range  of  adaptation  is  a  combination 


RESISTANT   VINES   AND    HYBRIDS.  11 

of  that  of  Riparia  and  of  Rupestris;  Nos.  3306  and  101U  being  also 
able  to  do  well  in  soils  a  good  deal  more  compact  in  nature  than  those 
suitable  for  either  of  the  parents;  No.  3309  stands  drought  well. 

Solonis  X  Riparia. — These  hybrids  are  well  known  for  the  heavy- 
bearing  character  they  communicate  to  their  grafts.  The  affinity  is 
very  good  and  they  are  particularly  well  adapted  to  wet  lands.  While 
adapted  to  the  same  soil-conditions  mentioned  above  for  the  Solonis, 
they  have  a  much  higher  resistance  to  phylloxera  than  the  latter. 
The  best  known  are  Nos.  1615  and  1616  (Couderc). 

Solonis  X  Cordifolia  X  Rupestris. — These  have  great  vigor,  which  they 
hold  from  the  Cordifolia  X  Rupestris,  while  they  take  some  of  the 
characters  of  the  Solonis  in  moist  locations.  They  have  proved  very 
valuable  in  heavy  moist  clays.  No.  202*  of  Millardet  and  Grasset  is 
among  the  best. 

Riparia  X  Cordifolia  X  Rupestris  (No.  1068). — Is  very  similar  to  the 
last  group  regarding  its  vigor,  but  is  adapted  more  particularly  to  very 
arid  locations,  where  it  has  proved  superior  even  to  the  Rupestris 
Martin.  It  will  probably  be  of  great  value  in  some  of  our  adobe  lands. 

Berlandieri  X  Riparias. — These  hybrids  have  been  studied  in  France, 
mainly  to  create  a  stock  having  the  resistance  of  the  Berlandieri  to 
chlorose,  and  the  easy  rooting  of  the  Riparias.  Some  of  the  selections 
have  given  very  satisfactory  results  (157,  420,  34E).  The  Berlandieri 
hybrids  are  very  productive  after  they  have  been  grafted.  The  roots 
are  very  strong  and  both  surface  and  deep  roots  are  abundant;  as  we 
said  before,  this  hybrid  may  prove  to  be  very  valuable  in  stiff,  dry  soils. 

VINIFERA  X  AMERICAN  HYBRIDS. 

Lenoir. — Though  the  question  of  the  origin  of  the  Lenoir  is  not  very 
well  settled,  it  probably  comes  in  this  group  of  Vinifera  X  American. 
The  Lenoir  has  a  great  affinity  for  the  Viniferas,  so  that  when  grafted 
in  the  field  it  gives  very  good  results.  It  does  not  root  as  well  from 
cuttings  and  does  not  bench-graft  as  well  as  the  Riparias  and  Rupestris, 
but  still  gives  satisfactory  results.  The  resistance  to  phylloxera  is  not 
high  (12-13),  which  is  too  low  unless  it  is  planted  in  a  soil  perfectly 
adapted  to  its  growth.  In  rich  soils,  fertile,  and  with  plenty  of  moisture, 
it  does  very  well,  but  these  are  also  good  Riparia  soils.  When  the  soil 
becomes  compact,  then  the  Lenoir  would  do  better  than  the  Riparia. 
But  for  these  heavy  lands  we  have  to-day  such  varieties  as  the  Solonis  X 
Cordifolia  X  Rupestris,  the  Riparia  X  Cordifolia  X  Rupestris,  the 
Riparia  X  Rupestris  101 u,  which  are  far  superior  to  the  Lenoir  in 
resistance,  and  ought  therefore  to  receive  the  preference. 


12  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 

Mourvedre  X  Rupestris  or  Mataro  X  Rupestris  is  a  very  fine  selection 
of  Vinifera  X  American;  the  1202  grows  well  in  all  soils  from  a  chalky 
land  to  a  deep  alluvial  one.  It  has  been  found  quite  resistant  to 
phylloxera,  and  particularly  well  adapted  to  heavy  clay  soils. 

Bourrisquou  X  Rupestris  and  Carignane  X  Rupestris  have  also  a  large 
range  of  adaptation,  but  are  specially  adapted  to  dry  locations. 

Aramon  X  Rupestris  (1  and  2)  are  found  to  do  splendidly  in  clay 
soils  of  medium  fertility  and  in  soils  underlaid  with  clay.  We  have  a 
great  many  of  these  soils  in  California,  and  this  stock  may  prove  to  be 
of  great  value.  The  roots  are  superficial,  like  those  of  the  Riparias, 
but  they  are  large  and  fleshy. 

MUNSON  HYBRIDS. 

Mr.  Munson  has  created,  in  recent  years,  a  great  many  hybrids  of 
Americo  X  Americans  and  of  Vinifera  X  Americans;  some  of  these  are 
quite  promising,  but  the  local  results  that  have  been  published  at 
different  times  can  not  be  taken  as  final  proof  of  their  value.  We  have 
not  yet  sufficient  data  to  give  personal  observations  on  these,  but  will 
give  the  opinion  of  Professors  Viala  and  Ravaz,  the  French  viticultural 
authorities,  on  some  of  the  Munson  resistant  stocks. 

Vitis  champini  (Candicans  X  Rupestris). — Can  be  divided  in  two 
groups:  the  glabrous  and  the  tomentose.  The  glabrous  group  has  a 
resistance  of  14,  the  tomentose  of  12.  They  are  harder  to  grow  from 
cuttings  than  the  Rupestris,  but  have  the  advantage  of  being  good 
growers  in  heavy  clays  and  of  having  large  wood.  Their  low  resistance 
is,  however,  a  grave  objection,  especially  when  we  have  some  varieties 
that  do  just  as  well  in  the  same  locations  and  which  are  much  more 
resistant. 

Candicans  X  Monticola  (Gwyn,  Sanford,  Belton). — The  latter  is  prob- 
ably the  best;  it  has  a  resistance  of  16,  is  very  vigorous,  has  a  large 
trunk,  does  well  in  compact  soils,  and  has  large  wood,  but  does  not 
grow  well  from  cuttings. 

Novo-Mexicana. — This  is  probably  a  Candicans  X  Riparia  X  Rupes- 
tris. The  Solonis,  Moobetie,  Hutchison,  and  Doaniana  are  some  of  the 
varieties  of  this  group.  They  are  adapted  to  Solonis  soils;  that  is,  rich, 
with  plenty  of  moisture.  They  do  well  in  lands  that  are  rather  wet 
and  salty  (alkali).  They  grow  well  from  cuttings  and  have  good-sized 
wood.  The  resistance  to  phylloxera  is  not  first  class,  but  is  sufficient 
in  soils  well  adapted  to  them.  In  lands  not  well  adapted,  they  suc- 
cumb rapidly  to  the  attacks  of  the  insect.  The  Hutchison  is  more 
vigorous  and  resistant;  the  Solonis  and  Doaniana  less  so. 


RESISTANT    VINES   AND    HYBRIDS.  13 

RESPECTIVE  VALUE  OF  AMERIGO  X  AMERICANS  AND  VINIFERA  x  AMERICANS. 

We  have  seen  that  in  both  of  these  groups  of  hybrids  we  may  find 
some  varieties  that  are  well  adapted  to  our  special  conditions;  in  both, 
we  find  a  good  resistance  to  phylloxera  in  the  selected  stock.  Which  of 
these  should  we  plant  in  our  vineyards? 

It  may  be  said  in  a  general  way  that  the  Americo  X  American 
hybrids,  as  well  as  the  ordinary  American  grafting  stocks,  make  the 
Vinifera  scions  that  are  grafted  on  them  bear  more  heavily  than  they 
would  if  they  were  on  their  own  roots.  They  come  into  full  bearing 
earlier,  and  generally  the  fruit  will  ripen  a  few  days  earlier.  But  the 
variety  of  Vinifera  grafted  on  these  roots  does  not  reproduce  exactly 
the  type  it  represents  when  on  its  own  roots:  the  grapes  may  be  larger, 
but  there  is  a  slight  difference  in  the  flavor  and  the  per  cent  of  sugar. 
The  Vinifera  vines  grafted  on  Vinifera  X  American  hybrids  retain  better 
their  original  qualities  and  have  a  better  affinity  between  stock  and 
scion. 

The  heavy  bearing  of  the  vines  grafted  on  Americans  or  on  Americo  X 
American  will  exhaust  the  land  sooner;  so  that  fertilizing  will  have  to 
be  resorted  to  earlier,  and  it  is  a  known  fact  that  heavy  fertilization 
affects  the  quality  of  the  grapes. 

From  these  remarks  we  may  conclude  that  the  American  resistant 
stock  and  their  hybrids  will  probably  be  favored  by  those  who  look  to 
quantity  more  than  to  quality;  while  for  the  fancy  wine  grapes  and  the 
better  grades  of  table  and  raisin  grapes  the  Vinifera  X  American 
resistant  stock  will  be  chosen.  The  choice  between  the  two  groups  is 
mainly  an  economic  question. 

A  warning  must  be  given  regarding  the  selection  of  the  stock.  We 
find  hundreds  of  thousands  of  hybrids  of  each  kind,  but  only  very  few 
have  been  carefully  selected.  Because  the  Riparia  X  Rupestris  3306  or 
3309  are  good,  it  is  by  no  means  a  reason  for  any  "  Riparia  X  Rupestris" 
to  be  equally  good.  The  number  of  the  selection  is  as  important,  and  in 
fact  more  important,  than  the  name  of  the  stock. 


UNIVERSITY  OF  CALIFORNIA  PUBLICATIONS. 


COLLEGE  OF  AGRICULTURE. 


AGRICULTURAL  EXPERIMENT  STATION. 


OBSERVATIONS  ON  SOME  VINE  DISEASES 

IN  SONOMA  COUNTY,  CALIFORNIA. 


BY  0.  BUTLER. 


BULLETIN    No.    168. 

(Berkeley,  Cal.,  May,  1905.) 


SACRAMENTO: 

w.  w.  SHANNON,     :     :     :     SUPERINTENDENT  OF  STATE  PRINTING. 

1905. 


BENJAMIN  IDE  WHEELER,  Ph.D.,  LL.D.,  President  of  the  University. 

EXPERIMENT  STATION  STAFF. 

E.  W.  HILGARD,  Ph.D.,  LL.D.,  Director  and  Chemist. 

E.  J.  WICKSON,  M.A.,  Horticulturist. 

W.  A.  SETCHELL,  Ph.D.,  Botanist. 

ELWOOD  MEAD,  M.S.,  C.E.,  Irrigation  Engineer. 

C.  W.  WOODWORTH,  M.S.,  Entomologist. 

R.  H.  LOUGHRIDGE,  Ph.D.,  Agricultural  Geologist  and  Soil  Physicist.    (Soils  and  Alkali.) 

M.  E.  JAFFA,  M.S.,  Assistant  Chemist.    (Foods,  Nutrition.) 

G.  W.  SHAW,  M.A.,  Ph.D.,  Assistant  Chemist.    (Starches,  Oils,  Beet-Sugar.) 

GEORGE  E.  COLBY,  M.S.,  Assistant  Chemist.    (Fruits,  Waters,  Insecticides.) 

RALPH  E.  SMITH,  B.S.,  Plant  Pathologist. 

A.  R.  WARD,  B.S.A.,  D.V.M.,  Veterinarian,  Bacteriologist. 

E.  W.  MAJOR,  B.Agr.,  Animal  Industry. 

A.  V.  STUBENRAUCH,  M.S.,  Assistant  Horticulturist,  in  charge  of  Substations. 

E.  H.  TWIGHT,  B.Sc.,  Diplom6  E.A.M.,    Viticulturist. 

F.  T.  BIOLETTI,  M.S.,    Viticulturist. 

WARREN  T.  CLARKE,  B.S.,  Assistant  Field  Entomologist. 

H.  M.  HALL,  M.S.,  Assistant  Botanist. 

H.  J.  QUAYLE,  A.B.,  Assistant  Entomologist. 

GEORGE  ROBERTS,  M.S.,  Assistant  Chemist,  in  charge  Fertilizer  Control. 

C.  M.  HARING,  D.V.M.,  Assistant  Veterinarian  and  Bacteriologist. 

0.  A.  COLMORE,  B.S.,  Clerk  to  the  Director. 


R.  E.  MANSELL,  Foreman  of  Central  Station  Grounds. 
JOHN  TUOHY,  Patron, 


.    Tulare  Substation,  Tulare. 
JULIUS  FORRER,  Foreman,  ' 

J.  E.  McCOMAS,  Patron,  Pomona,  -^ 

J.  W.  MILLS,  Superintendent,  Pomona, 

^    Southern  California  Substation, 
In  charge  Cooperation  Experiments  of  southern  California, 

JOHN  H.  BARBER,  Assistant  Superintendent,  Ontario, 

J.  W.  ROPER,  Patron, 

HENRY  WIGHTMAN,  In  charge 

ROY  JONES,  Patron, 


y  University  Forestry  Station,  Chico. 


WM.  SHUTT,  Foreman,        University  Forestry  Station' 

H.  O.  WOODWORTH,  M.S.,  Foreman  of  Poultry  Station,  Petaluma. 


The  Station  publications  (REPORTS  AND  BULLETINS),  so  long  as  avail- 
able, will  be  sent  to  any  citizen  of  the  State  on  application. 


CONTENTS. 


THE  RED-LEAF  DISEASE... 

DESCRIPTION  OF  THE  DISEASE  AND  ITS  RELATIONSHIPS 6 

Effect  of  the  disease  on  the  leaves 6 

Effect  of  the  disease  on  the  fruit 8 

Effect  of  the  disease  on  the  shoots , 9 

The  relationships  of  the  Red-leaf  disease 9 

Resemblance  between  the  Red-leaf  disease  and  the  Folletage_.  9 

Resemblance  between  the  Rougeot  and  the  Red-leaf  disease 10 

Resemblance    between   the   Red-leaf  disease  and  the  California  (or  Anaheim) 
vine  disease 10 

RESULTS  OF  WINTER  AND  SUMMER  SPRAYING  EXPERIMENTS... 11 

Details  of  the  work  at  the  South  Sonoma  Experiment  Plot 13 

THE  GRAPE-SHRIVEL ..  18 

Description ... 18 

Effect  of  the  disease  on  the  grapes 18 

Effect  of  the  disease  on  the  leaves 19 

Internal  appearance  of  the  shoots,  spurs,  arms,  and  body  of  vines 20 

Generalities  regarding  the  work  at  the  East  Sonoma  Experiment  Plot 21 

Cause  of  the  Grape-Shrivel 23 

ROOT-ROT  __  .-24 


OBSERVATIONS  ON  SOME  VINE  DISEASES  IN  SONOMA 
COUNTY,  CALIFORNIA. 

BY  O.  BUTLER. 


Introduction. — In  1903  the  Viticultural  Department  of  the  College  of  Agriculture  of  the 
University  of  California  took  up  the  study  of  a  disease  that,  for  a  few  seasons,  had  been 
observed  in  Sonoma  County  and  was  beginning  to  cause  some  anxiety  among  the  vine- 
yardists.  After  an  inspection  of  the  vineyards  of  Sonoma  County  from  Santa  Rosa  to 
Cloverdale,  including  those  of  Alexander  Valley  and  Dry  Creek,  we  found  that  the 
"Red-leaf  disease,"  as  the  malady  was  called,  was  sufficiently  widespread  to  require 
special  attention.  The  "Red-leaf  disease"  was,  at  that  time,  associated  by  many  per- 
sons with  the  Anaheim  disease,  and  by  some  with  Anthracnose.  The  first  theory  was 
set  aside  h  priori,  on  account  of  the  difference  in  the  effect  on  the  canes  and  grapes,  and 
also  on  account  of  the  lack  of  virulence  of  the  disease  when  attacking  the  Mission  vines.* 
The  suggestion  that  it  might  be  Anthracnose  was  easily  set  aside,  as  the  markings  of 
the  disease  on  leaves,  canes,  and  berries  are  of  an  entirely  different  character;  it  is  very 
doubtful  that  the  true  Anthracnosef  has  ever  been  found  in  a  vineyard  of  California. 

On  my  return  from  this  trip  of  investigation,  I  passed  through  Xapa  Valley  to  com- 
pare the  "  Red-leaf  disease"  with  a  malady  of  similar  character  that  had  caused  damage 
in  some  sections,  and,  after  a  consultation  with  Dr.  E.  W.  Hilgard,  it  was  decided  to 
start  a  methodic  study  of  the  "Red-leaf  disease,"  and  Mr.  O.  Butler  was  appointed  to 
carry  out  the  investigations.  This  bulletin  gives  the  results  of  his  preliminary  obser- 
vations. 

During  the  same  season  arrangements  were  made  with  several  vineyardists  to 
establish  experiment  plots  on  their  land  during  the  following  year. 

While  investigating  the  "Red-leaf  disease,"  Mr.  Butler  found  that  a  number  of  mala- 
dies, either  parasitic  or  physiological,  wrere  responsible  in  a  measure  for  the  weakness  or 
dying  of  the  vines.  Among  these  affections  Phylloxera,  Root-rot,  Mildew,  lack  of  affinity 
between  scion  and  stock,  lack  of  adaptation  of  stock  to  soil,  mechanical  injuries,  Erinose, 
and  Black-knot  are  quite  prevalent  in  Sonoma  County,  as  well  as  in  most  vineyard 
districts  of  California. 

A  description  of  some  of  these  will  be  given  in  separate  bulletins,  while  others  have 
been  already  discussed  in  former  publications:  Report  of  Viticultural  Commission, 
1893;  Bulletins  Nos.  127,  131,  146,  148,  of  the  Agricultural  Experiment  Station  of  the 
University  of  California.:}: 

Mr.  Butler's  observations  seem  to  show  that  the  cause  of  the  Red-leaf  disease  is  not 
parasitic,  but  that  it  is  more  probably  due  to  soil  and  atmospheric  conditions.  These 
observations  will  be  kept  up  during  the  coming  season,  and  a  careful  examination  of  the 
subsoil  and  moisture-contents  of  the  experimental  plots  will  be  made  through  the  grow- 
ing season,  so  that  definite  conclusions  may  be  drawn. 

E.  H.  TWIGHT. 

THE  RED-LEAF  DISEASE. 

In  1903,  the  attention  of  the  public  was  aroused  by  the  alarming 
notices  published  in  the  Sonoma  County  papers  about  a  new  and  mys- 
terious malady,  which  was  unanimously  denominated  Red-leaf  disease. 
Opinions  were  freely  aired  as  to  the  nature  of  the  disease,  but  the 

*  N.  B.  Pierce,  Bulletin  No.  2,  Div.  Veg.  Path.,  U.  S.  Dept  Agr.,  page  7. 
fSphaceloma  ampelinum. 

JAlso,  in  "American  Vines,"  by  P.  Viala  and  Ravaz ;  translated  from  the  French  by  R  Dubois 
and  E.  H.  Tvvight. 


6  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 

disease  itself  was  not  described.  The  reader  was  left  to  conjecture, 
from  the  name  the  grape-growers  were  agreed  upon  giving  to  it,  that  a 
red  leaf  was  its  main  characteristic.  Beyond  this,  however,  the  grape- 
growers  did  not  entirely  agree ;  the  term  red  leaf  is  indefinite  enough 
to  allow  of  a  wide  individualistic  interpretation,  and  the  grower  who 
had  vines  suffering,  or  dying,  from  a  cause  undiscoverable  to  him,  and 
showing  a  foliage  tinted,  perchance,  here  and  there  with  red,  was 
inclined  to  call  the  trouble  from  which  his  vines  were  suffering  the 
Red-leaf  disease.  This  diversity  of  opinion  was  at  first  rather  confusing, 
and  was  more  a  hindrance  than  a  help  in  furthering  the  investigations. 
In  fact,  of  the  three  vineyards  kept  constantly  under  observation,  only 
one  was  finally  found  to  be  free  from  any  other  disease  than  the  Red- 
leaf  ;  and  the  development  and  characteristics  of  the  said  disease  in 
this  vineyard  were  a  great  help  in  diagnosing  the  malady  in  other 
parts  of  the  county,  and  under  less  favorable  circumstances. 

The  result  of  our  investigations  of  the  disease  under  consideration 
may  be  conveniently  divided  into  two  parts  :  (1)  Description  of  the 
Red-leaf  disease  and  its  relationships  ;  and  (2)  Results  of  the  winter  and 
summer  spraying  experiments  instituted  to  combat  it. 

DESCRIPTION    OF    THE    DISEASE    AND    ITS    RELATIONSHIPS. 

The  Red-leaf  disease  may  affect  the  shoots,  the  leaves,  the  peduncles, 
the  pedicel,  and  the  fruit  of  the  vine;  it  may  affect  the  uppermost  part 
of  a  cane,  or  several  canes;  one  entire  side  of  a  vine,  or,  but  more 
rarely,  an  entire  vine.  One  vine  may  show  all  the  characteristics  of 
this  disease,  and  another  only  a  part,  or  perhaps,,  only  one  of  them- 
The  disease  may  never  proceed  beyond  the  first  stages,  a  not  uncommon 
feature,  or  it  may  develop  sloAvly  until  all  its  characters  are  patent  to 
the  most  casual  observer;  more  often,  however,  its  development  is  rapid, 
and  it  would  be  somewhat  difficult  to  distinguish  the  first  stage,  which  is 
rather  obscure,  from  those  final  stages  which  characterize  it  particularly. 

Allowing,  then,  for  the  irregularities  in  the  development  of  the  Red- 
leaf  disease,  and  for  the  absence  of  anything  like  progression  from  one 
stage  to  another,  the  reader  will  find  in  the  following  description  the 
means  of  identifying  this  disease,  without  much  difficulty,  whenever  it 
occurs  in  his  vineyard. 

Effect  of  the  Disease  on  the  Leaves. — The  leaves  near  the  apex  of  the 
shoots,  including  those  recently  expanded,  and  perhaps  for  a  foot  or  two 
down,  become  pale,  especially  in  the  interveinar  spaces.  If  a  leaf  in  this 
stage  is  picked  and  observed  by  transmitted  light,  and  with  the  under- 
side facing  the  eye,  all  the  fine  network  of  veins  will  be  found  to  be 
discolored.  This  discoloration  of  the  small  veins  appears  simultane- 
ously with  the  loss  of  color  in  the  leaves;  in  the  recently  expanded 


OBSERVATIONS   ON   SOME   VINE   DISEASES   IN   SONOMA   COUNTY.  7 

leaves,  which  are  naturally  yellowish-green,  this  discoloration  is  more 
indicative  of  the  disease  than  the  change  in  color.  Following  the  loss  of 
color,  the  leaves  become  somewhat  convex  and  the  edges  curl  toward 
the  lower  surface;  they  lose  their  natural  appearance;  the  tissue 
between  the  main  veins  sinks,  and  the  veins  themselves  stand  out  like 
ribs.  In  mild  cases  the  disease  may  develop  no  further  than  this.  The 
affected  leaves,  however,  fall  off  sooner  or  later,  and  generally  with 
their  stalks  (petioles). 

In  severe  cases  of  the  disease,  the  recently  expanded  leaves  may  dry 
up  suddenly  and  totally  without  malformation  of  any  kind;  or,  as 
occurs  more  frequently,  the  parenchyma  becomes  pale  yellowish-green, 
and  the  inclosed  network  of  small  veins  discolored;  then,  usually,  the 
lobe,  or  at  least  the  upper  portion  of  it,  or  in  entire  leaves  that  portion 
of  the  parenchyma  which  occupies  the  equivalent  position,  including 
one  wing  of  the  petiolary  sinus,  becomes  more  or  less  convex  and  the 
tissue  sunken  between  the  veins,  which  stand  out,  often  in  bold  relief. 

At  this  stage  the  tissues  begin  to  dry  rapidly  from  the  periphery  toward  the  petiole, 
at  the  same  time  retaining  their  peculiarity  of  form.  When  dry,  the  tissues  are  brittle 
and  reddish  brown.  As  soon  as  the  discoloration  has  reached  the  petiole,  the  entire 
leaf  and  leaf-stalk  may  fall  together.  In  older  leaves,  those  not  yet  fully  developed  and 
still  growing,  one  observes  great  variations— variations  which  can  not  be  accounted  for 
by  the  position  of  the  leaf  in  relation  to  other  diseased  leaves,  or  by  its  age.  Some  leaves 
show  the  characteristics  just  described  as  typical  of  recently  expanded  ones,  except 
that  they  do  not  fall  prior  to  the  dying  of  the  convex  and  furrowed  area.  The  drying 
of  that  portion  of  the  leaf  proceeds  as  rapidly  in  one  case  as  in  the  other.  In  the  more 
fully  developed  leaves,  however,  the  action  is  sufficiently  striking.  At  the  petiole,  and 
in  the  region  immediately  adjoining  it,  the  mid-rib  serves  as  a  line  of  demarkation 
between  the  living  and  the  dead  tissues.  The  dead  tissue  soon  separates  from  the 
petiole,  which,  in  turn,  discolors.  At  this  stage  the  leaf-blade  separates  from  the  petiole, 
which,  though  drying  up  and  discoloring  more  or  less  from  the  apex  down,  remains  a 
while  longer  attached  to  the  shoot.  In  other  cases,  besides  the  dead  and  furrowed  area, 
there  may  appear  between  the  veins,  on  other  parts  of  the  leaf,  spots  which,  at  first  yel- 
lowish, become,  at  the  same  time  as  the  aforementioned  area,  dry  and  reddish-brown 
in  color,  except  for  a  narrow  margin  next  to  the  still  green  or  greenish-yellow  tissue. 
Or  again,  the  leaves  may  present  the  following  appearance:  The  leaf-tissue,  while  still 
green,  becomes  sunken  between  the  veins;  then,  in  one  or  sometimes  both  corners,  the 
leaf  becomes  pale  greenish-yellow  and  between  the  veins,  in  the  remainder  of  the  leaf, 
appear  spots  of  various  sizes  of  the  same  color.  These  spots  enlarge  and  even  run 
together  to  form  stripes.  At  this  stage  the  discolored  areas  begin  to  dry  rapidly,  assum- 
ing the  familiar  reddish-brown  color.  The  tissues  next  the  petiolary  sinus  rapidly  dry 
up  from  the  periphery  inwards,  but  do  not  encroach  upon  the  mid-rib,  and  one  may 
sometimes  find  a  leaf  which  still  adheres  to  its  stalk,  after  the  parenchyma  on  each 
side  has  become  detached.  A  slight  margin  of  yellowTish-green  sometimes  separates  the 
dead  furrowed  area  from  the  still  living  tissues;  this  margin  of  yellow  is,  however, 
generally  more  distinct  around  the  spots  and  stripes  of  dead  tissue  in  the  other  parts  of 
the  parenchyma.  The  leaves  fall  from  the  petioles,  which  soon  followr  them. 

In  fully-developed  leaves  and  old  leaves,  the  disease  is  not  accom- 
panied by  any  distortion  or  furrowing  of  the  leaf-blade.  It  affects  only 
the  tissues  between  the  main  veins,  and  first  appears  as  suffused  green- 
ish-yellow spots,  which,  at  first  indefinite,  become  gradually  larger  and 
more  definite  in  outline,  and  often  merge  together,  forming  large  macu- 


8  UNIVERSITY    OF   CALIFORNIA — EXPERIMENT   STATION. 

lations  and  stripes,  which  are  more  or  less  yellow — the  intensity  of  the 
colorations  depending,  it  would  seem,  on  the  rapidity  with  which  the 
disease  has  progressed.  The  center  of  the  spot  now  dies,  becoming 
reddish-brown,  sometimes  almost  with  a  brick  tint  and  a  sub-glossy 
appearance  when  death  has  been  rapid.  According  to  the  rapidity  of 
death  these  spots  or  stripes  are  surrounded,  either  (a)  with  a  thin 
border  of  dull,  deep  red,  which,  in  turn,  is  separated  by  a  suffused 
yellow  or  greenish-yellow  band  from  the  green  of  the  still  healthy  sur- 
rounding tissues;  or  (b)  with  a  border  of  yellow,  either  suffused  and 
broad,  or  thin  and  with  a  more  definite  margin;  or  (r)  directly  by 
the  healthy  green  tissue  itself.  Sometimes  the  old  leaves  near  the  base 
of  the  shoots  show  a  slight  variation  from  the  characteristics  just 
described.  These  leaves,  as  soon  as  the  disease  begins  to  appear  between 
the  veins  and  the  spots  enlarge  and  merge  to  form  stripes,  become  more 
or  less  greenish-yellow  in  the  entire  parenchyma.  The  dead  areas, 
instead  of  being  reddish-brown  and  in  sharp  contrast  to  the  living 
tissues,  are  fawn-colored  and  soft,  crumbly,  tear  easily,  and  fall  away. 
The  affected  leaves  thus  become  deeply  incised,  sometimes  almost  to  the 
petiole,  from  which  they  hang  in  two,  three  or  more  pieces. 

In  the  case  just  described,  as  likewise  in  the  preceding,  the  leaves 
may  remain  attached  to  the  shoots  for  an  indefinite  time,  and  when 
they  fall  it  may  be  either  with  the  petioles,  or  before  them. 

Effect  of  the  Disease  on  the  Fruit. — The  fruit  of  white  varieties  of 
grapes  appears  to  be  more  sensitive  to  the  Red-leaf  disease  than  that 
of  black  varieties.  It  would  seem  that  the  latter  show  the  character- 
istics of  this  disease  more  markedly  on  the  foliage,  except  in  severe 
cases,  and  toward  autumn,  whereas  in  the  former  the  disease  is  more 
conspicuous  on  the  berries. 

The  Red-leaf  disease  may  affect  the  fruit  soon  after  setting.  When 
this  occurs,  on  passing  the  hand  over  a  diseased  bunch  of  grapes,  the 
berries  come  off  either  with  or  without  the  pedicels.  They  even  fall  of 
themselves,  and  the  stem  (peduncle)  dries  up  and  falls  also.  This 
manifestation  of  the  disease  is  more  frequent  among  the  red  than  the 
white  grapes.  The  more  noteworthy  characters  begin  to  show  unmis- 
takably on  the  berries  when  the  clusters  of  grapes  are  a  month  or  a 
month  and  a  half  old,  and  only  become  general  just  prior  to  the  begin- 
ning of  maturation.  The  berries  become  suffused  with  livid  discolora- 
tions,  which  are  sub-cuticular,  the  cuticle  itself  not  being  affected  until 
later.  The  tissue  of  the  berries  in  the  center  of  these  spots  generally 
falls  away  from  the  epidermis,  which  then  collapses.  The  livid  and 
sunken  spots  thus  formed  may  be  more  or  less  numerous,  and  large  or 
small;  they  are  more  frequent  on  the  exposed  berries  than  on  those  in 
constant  shade;  they  are  more  frequent  on  the  sides  of  the  berries 
exposed  to  the  light  than  on  the  shady  sides.  When  they  do  not  fall 
off  at  this  stage,  the  berries  shrivel  and  dry  up. 


OBSERVATIONS   ON   SOME   VINE   DISEASES   IN   SONOMA   COUNTY. 

When  the  berries  become  affected  just  previous  to  maturity,  or  after 
maturity  has  begun,  they  ripen  imperfectly  and,  as  a  rule,  are  never 
worth  picking.  The  clusters  of  diseased  grapes  are  generally  allowed 
to  remain  on  the  vine,  and,  after  defoliation,  they  may  be  observed 
hanging  from  the  canes. 

Effect  of  the  Disease  on  the  Shoots. — The  shoots  are  not  affected  directly 
by  the  Red-leaf  disease.  The  symptoms  they  show  are  a  consequence, 
so  to  speak,  of  the  intensity  of  the  malady  on  the  leaves.  When  the 
shoots  are  partially  defoliated  (counting  from  the  apex),  their  growth 
is  only  checked  for  a  while.  When  the  defoliation  is  more  severe,  the 
apex  curls  somewhat,  discolors  and  dies.  Death,  however,  is  not  con- 
fined to  the  apex,  but  proceeds  for  a  greater  or  less  distance  down  the 
shoots,  the  discoloration  progressing,  as  it  were,  by  stages.  The  shoots 
shrink  and  gradually  turn  brown.  The  shrinkage  of  the  tissues  is  most 
noticeable  near  the  nodes,  and,  except  in  more  lignified  parts  of  the 
shoots,  always  precedes  the  discoloration.  The  discoloration  of  the 
shoots  is  somewhat  irregular,  and  more  rapid  in  the  parts  exposed  to 
the  sun.  When  defoliation  is  complete,  the  shoots  sometimes  die  from 
apex  to  base.  When  they  are  not  defoliated,  their  lignification  does 
not  seem  to  be  materially  interfered  with,  though  it  is  often  irregular. 
One  may  even  find,  in  rare  cases,  green  immature  spots  or  stripes  in 
the  midst  of  lignified  tissue,  but  even  such  an  irregularity  as  this  does 
not  persist.  The  immature  spots  mature  in  time. 

The  Relationships  of  the  Red-leaf  Disease. — The  Red-leaf  disease 
appears  more  or  less  closely  related  to  the  Folletage,  the  Rougeot,  and 
the  California  Vine  disease.  It  resembles  the  Folletage  by  the  sporadic 
suddenness  with  which  it  sometimes  appears;  the  Rougeot,  in  its  not 
being  immediately  fatal,  and  possibly  also  in  some  of  its  foliar  colora- 
tions; and  the  California  (Anaheim)  vine  disease  in  the  striping  of  the 
leaves. 

The  cause  of  the  Folletage  and  of  the  Rougeot  has  been  thought  to  be 
due  to  the  rupture  of  equilibrium  between  transpiration  and  absorption, 
but  that  of  the  California  vine  disease  has  not  been  determined.  In 
the  case  of  the  Red-leaf  disease,  the  evidence  gathered  in  a  single  season 
seems  to  point  to  a  physical  rather  than  to  a  parasitic  cause. 

Resemblance  between  the  Red-leaf  Disease  and  the  Folletage. — The 
Folletage  affects  the  vines  in  midsummer.  "One*  sometimes  observes, 
especially  in  July  and  August,  vines  in  excellent  health  dying  suddenly 
in  a  vineyard.  The  leaves  wilt,  fade,  and  dry;  the  shoots  and  even  the 
arms  succumb.  The  vines  may  die  in  a  few  minutes.  *  *  *  It  is 
only  isolated  vines  (they  may  sometimes  be  numerous)  which  are 
affected  by  this  disease;  *  *  *  a  whole  vineyard  is  never  affected. 
Entire  shoots,  or  even  whole  arms,  may  be  destroyed  on  a  diseased  vine 

*P.  Viala:  "  Les  Maladies  de  la  Yigne,"  page  471. 


10 


UNIVERSITY    OF   CALIFORNIA — EXPERIMENT   STATION. 


without  the  other  arms  or  shoots  being  affected."  Vines  planted  in 
"deep,  cool,  damp  soils"  are  subject  to  this  trouble,  especially  when 
heat  follows  heavy  rains.  In  dry  soils  the  Folletage  also  occurs.  In 
both  cases  it  is  due  to  a  rupture  of  the  equilibrium  between  the  trans- 
piration of  the  leaves  and  the  absorption  of  the  roots.  The  resemblance 
between  the  effect  of  the  Folletage  and  that  of  the  Red-leaf  disease  is 
not  a  very  close  one.  The  Red-leaf  disease  is  apparently  not  fatal  in  a 
single  season,  if  ever.  Like  the  Folletage,  however,  it  affects  the  vines 
with  greatest  intensity  and  suddenness  during  July  and  August,  and 
more  frequently  partially  than  wholly.  The  death,  either  total  or 
partial,  of  the  affected  shoots  does  not  follow  the  attack  in  the  great 
majority  of  cases.  In  some  cases  of  Folletage,  the  foliar  characteristics 
are  very  similar  to  those  of  vines  affected  with  the  Red-leaf  disease,  if 
we  may  judge  from  plates  17,  18,  and  19  given  as  illustrations  of  this 
disease  in  Bulletin  No.  2  of  the  Division  of  Vegetable  Pathology,  U.  S. 
Department  of  Agriculture. 

Resemblance  between  the  Rougeot  and  the  Red-leaf  Disease. — -The  Rou- 
geot  is  considered  by  some  authors  as  a  mild  form,  so  to  speak,  of  the 
Folletage,  and  attributable  to  the  same  cause.  The  Rougeot  affects 
vines  as  sporadically  and  irregularly  as  the  Red-leaf  disease.  Its  foliar 
characteristics  remind  one  of  those  of  the  Anaheim,  or  the  Red-leaf 
disease.  Vines  affected  with  Rougeot  generally  recover. 

Resemblance  between  the  Red-leaf  and  the  California  (or  Anaheim) 
Vine  Disease. — For  a  description  of  this  disease  the  reader  is  referred 
to  Pierce's  memoir  on  the  subject.*  To  describe  the  disease,  even  in 
the  most  summary  manner,  is  not  necessary  in  the  present  publication. 
The  California  vine  disease  and  the  Red-leaf  disease  are  sufficiently 
different  from  each  other,  in  their  salient  characteristics,  to  be  easily 
distinguished  without  resorting  to  details.  The  reader  will  find,  in  the 
following  comparison,  a  sufficient  proof  of  the  distinctiveness  of  these 
two  diseases: 


Anaheim  Disease.^ 

The  disease  is  cumulative. 

The  newly-formed  leaf  either  remains 
green  or  is  striped  yellow  or  red,  accord- 
ing as  the  grapes  are  white  or  red.  (loc. 
cit.,  page  142.) 

As  a  rule  the  leaves  fall  from  the  base  of 
the  canes  first,  (loc.  cit.,  page  45.) 

The  roots  are  decayed,  (loc.  cit.,  page  57, 
et  suiv.) 

Grapes  dry  and  remain  on  the  vine,  or  fall 
off,  but  not  very  frequently,  (loc.  cit., 
page  53.) 

A  diseased  vine  shows  the  disease  most 
generally  on  all  its  shoots,  (loc.  cit., 
page  79.) 


Red-leaf  Disease. 

The  disease  is  not  cumulative. 

The  newly-formed  leaves  either  dry  with 
deformation  (leaves  just  expanded)  or  a  re 
paler  than  normally  and  convex  (leaves- 
two  or  more  nodes  from  the  apex). 

The  leaves  fall  from  the  apex  first. 

The  roots  are  healthy. 

Grapes  are  mottled  with  livid,  sunken 
spots. 

The  number  of  shoots  affected  is  variable, 
though  rarely  total. 


*Bull.  No.  2,  Div.  Veg.  Path.,  U.  S.  Dept. 
fN.  B.  Pierce:  "California  Vine  Disease, 


Agr. 

"  loc.  cit. 


OBSERVATIONS    ON    SOME    VINE   DISEASES   IN    SONOMA    COUNTY. 


11 


The  above  consideration  of  the  relations  of  the  Red-leaf  disease  leads 
one  to  conclude  that  the  Red-leaf  and  the  Rougeot  are  the  more  closely 
related.  If  this  conclusion  is  proved  to  be  correct,  then  the  grower 
need  not  feel  greatly  alarmed  even  when  a  considerable  percentage  of 
his  vines  are  affected  with  the  Red-leaf  disease. 

RESULTS    OF    WINTER    AND    SUMMER  SPRAYING    EXPERIMENTS. 

Toward  the  end  of  January,  1904,  the  active  help  of  three  growers, 
who  were  anxious  to  find  a  remedy  for  the  Red-leaf  disease,  was 
obtained.  The  vineyards  of  these  growers  are  situated  respectively  in 
the  south,  in  the  north,  and  in  the  east  of  Sonoma  County. 

Those  portions  of  their  vineyards  supposed  to  be  most  affected  with 
this  disease  were  selected  for  experimental  purposes.  It  had  been  our 
intention  to  divide  the  plots  off  and  to  spray  them  after  the  manner 
shown  in  the  following  diagram,  but  owing  to  inclement  weather  the 
spraying  with  the  iron  sulfate  was  not  completely  carried  out,  except 
at  the  East  Sonoma  experiment  plot. 


1.    Arrangement  of  Experiment  Plots. 


1 

2 

3 

4           5 

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11 

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8 

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10 

11 

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12 


The  TVor^/t  Sonoma   experiment  plot  was  not  sprayed  with  the  iron 
sulfate  at  all,  and  the  diagram  of  the  plot  as  sprayed  would  be: 


Bordeaux  mixture 


Witness 


Bordeaux  mixture 
Witness 


Bordeaux  mixture 


12 


UNIVERSITY    OF   CALIFORNIA  — EXPERIMENT   STATION. 


The  sprays  used,*  the  dates  of  their  application,  the  amount  of  each 
used  per  acre,  and  the  length  of  the  vine  shoots  when  they  were  applied, 
are  given  in  the  following  tables.  From  these  tables  the  cost  of  the 
spraying,  exclusive  of  the  labor,  may  be  approximately  determined: 

Amount  of  spray  used  on  fair  vines  of  the  Burger  variety;  1210  vines  per  acre. 


Date. 

Acid  Iron 
Sulfate. 

Bordeaux 
Mixture. 

Average  Length 
of  Canes. 

May  3  and  4 

Was  unable  to 

70  gallons 

9  inches 

May  93 

use  this  spray 

85  gallons 

30  inches 

June  7         -  -              -                     -   - 

on  account  of 

100  gallons 

36  inches 

Julv  19  -. 

bad  weather. 

140  gallons 

'  3.5-4  feet 

On  the  South  Sonoma  experiment  plot  half  of  the  intended  spraying 
with  the  iron  sulfate  was  carried  out. 

Amount  of  spray  used  on  old,  large  vines  of  the  Mission  variety;  680  vines  per  acre. 


Date. 

Acid  Iron 
Sulfate. 

Bordeaux 
Mixture. 

Average  Length 
of  Cane. 

. 

February  2    _ 

400  gallons 

none 

0 

April  28 

none 

80  gallons 

9  inches 

May  13 

none 

105  gallons 

20  inches 

June  14  and  15_       -       _   _   _ 

none 

270  gallons 

3.5-5  feet 

July  18 

none 

530  gallons 

4-6  feet 

The  growth  of  the  vines  at  the  East  Sonoma  experiment  plot  was  too 
uneven  to  be  of  value  for  tabulation. 

The  three  experiment  plots  very  soon  proved  to  be  of  very  unequal 
value  for  the  study  of  the  Red-leaf  disease.  The  vines  in  the  East 
Sonoma  plot  were  practically  not  affected  by  this  disease,  though  seri- 
ously menaced  by  one  which  will  be  described  below  under  the  name  of 
Grape-shrivel.  The  Red-leaf  disease  was  prevalent  in  the  North  Sonoma 
plot,  but  so  also  was  the  Root-rot.  At  the  South  Sonoma  plot,  however, 
the  vines  were  not  affected  with  any  other  disease  than  the  Red-leaf, 
and  it  is  there  that  practically  all  the  data  on  the  development  and 
progress  of  this  malady  were  gathered.  Notwithstanding  the  presence 

*The  sprays  used  were:  1.25  per  cent  Bordeaux  mixture,  and  acid  iron  sulfate.  The 
acid  iron  sulfate  is  prepared  as  follows:  Ten  pounds  of  iron  sulfate  are  placed  in  a  half- 
barrel,  one  pound  of  commercial  sulfuric  acid  is  poured  into  the  copperas  (to  prevent 
sputtering,  which  is  objectionable,  the  acid  should  always  be  added  before  the  water), 
then  12.5  gallons  of  water  are  added  and  the  mass  stirred  until  the  sulfate  has  dissolved. 
In  making  large  quantities  of  the  acid  iron  sulfate  spray  it  is  more  expeditious  to  use 
hot  water.  The  iron  sulfate  is  only  a  winter  spray,  and  can  not  be  used  after  the  buds 
have  swollen. 


OBSERVATIONS   ON    SOME   VINE   DISEASES   IN   SONOMA   COUNTY. 


13 


of  other  diseases,  the  North  Sonoma  plot,  and  a  few  side  excursions  to 
other  vineyards,  were,  however,  of  valuable  assistance  as  soon  as  some 
knowledge  of  the  characteristics  of  the  Red-leaf  disease  had  been 
obtained.  By  their  aid  the  limits  of  variability  of  these  characteristics 
were  established  with  considerable  accuracy. 

In  the  following  discussion  of  the  effect  of  our  spraying  experiments 
in  controlling  the  Red-leaf  disease,  together  with  the  observations  on 
its  progress  and  development  in  the  vineyard,  the  data  collected  at  the 
South  Sonoma  experiment  plot  form  the  basis  of  our  discussion. 

Details  of  the  Work  at  the  South  Sonoma,  Experiment  Plot. — The  plot 
was  established  among  old  Mission  vines  which  had  been  more  or  less 


HflY  TlEU) 


FIG.  1.    Map  of  South  Sonoma  Experiment  Plot. 

diseased  in  1902  and  1903  and  were  beginning  to  cause  some  concern. 
By  referring  to  the  map  (Fig.  1)  the  reader  will  at  once  see  the  manner 
in  which  the  plot  was  laid  off  and  sprayed.  The  times  at  which  the 
sprayings  were  given  have  already  been  mentioned.  The  interval 
between  the  sprayings  with  the  Bordeaux  mixture  was  so  timed  as  to 
always  keep  the  leaves  well  covered  with  a  film  of  the  fungicide.  The 
Bordeaux  was  observed  to  cause  a  certain  amount  of  burning  in  the 
young  leaves,  especially  in  the  earlier  part  of  the  season.  This  burning 
of  the  tissues,  which  occurs  between  the  veins  and  in  stripes,  the  leaves 
becoming,  as  a  consequence,  somewhat  crinkled  and  distorted,  should 
not  be  confused  with  the  characteristics  of  the  Red-leaf  disease.  The 


14  UNIVERSITY    OF   CALIFORNIA — EXPERIMENT   STATION. 

vines  sprayed  with  the  acid  iron  sulfate  were  greener  than  the  wit- 
nesses, at  least  during  the  first  part  of  the  growing  season ;  the  vines 
sprayed  with  the  Bordeaux  mixture  were  much  greener  than  the  wit- 
nesses, even  in  the  height  of  summer.  This  improvement  in  the  color 
of  the  foliage,  where  and  whenever  the  above  fungicides  are  used,  occurs 
regardless  of  the  presence  or  absence  of  disease. 

The  Red-leaf  disease  first  appeared  in  the  plot  on  the  10th  of  June, 
when  a  single  vine  was  found  somewhat  affected.  On  the  10th  of  July 
there  was  hardly  more  than  one  per  cent  of  the  vines  affected.  From 
then  to  the  end  of  the  season,  however,  the  disease  rapidly  increased. 
On  the  25th  of  August  about  ten  per  cent  of  the  vines  were  affected, 
which  gives  an  increase  of  nine  per  cent  in  thirty-six  days.  From  the 
25th  of  August  to  the  13th  of  October-,  the  increase  was  only  five  per 
cent. 

If,  instead  of  considering  the  plots  as  a  whole,  we  compare  the  percentages  of 
diseased  vines  among  the  sprayed  and  unsprayed  rows,  we  will  find  that  the  Red-leaf 
disease  develops  almost  as  freely  in  the  one  case  as  in  the  other,  with  one  exception. 
In  the  case  of  the  witnesses  (average  of  seven  sections)  the  disease  is  more  rapid  from 
the  10th  to  the  28th  of  July  than  in  the  case  of  the  sprayed  vines  ;  but  between  July  28th 
and  August  25th  it  is  proportionately  less  rapid  than  among  the  vines  sprayed  with  the 
acid  iron  sulfate  and  not  much  greater  than  among  those  sprayed  with  the  Bordeaux 
mixture.  The  rapid  rise  in  the  percentage  of  diseased  vines  in  the  sprayed  rows  begins 
later  than  in  the  average  of  the  witnesses,  and  on  the  28th  of  July.  On  the  12th  of 
August  the  vines  sprayed  with  the  iron  sulfate  show  a  greater  percentage  of  diseased 
vines  than  the  witnesses,  and  throughout  the  remainder  of  the  season  continue  to  do  so. 
Among  the  vines  sprayed  with  the  Bordeaux  mixture  the  percentage  of  disease  remains 
below  that  of  the  witnesses,  except  on  the  13th  of  October,  when  it  is  almost  one  percent 
higher.  The  vines  sprayed  with  the  iron  sulfate  and  Bordeaux  mixture  (one  section) 
showed  1.6  per  cent  diseased  vines  all  through  July;  between  July  28th  and  August  12th 
the  percentage  increased  to  5.4  per  cent,  and  from  that  date  until  October  13th  the 
number  of  diseased  vines  gradually  increased  until  it  reached  9.3  per  cent.  (See  Fig.  2.) 

The  distribution  of  the  diseased  vines  in  the  plot  is  quite  sporadic. 
The  disease  does  not  progress  from  any  one  center,  or  many  centers. 

In  the  map  (Fig.  1)  the  position  of  the  diseased  vines  on  October  13th 
is  marked  by  a  circle;  the  crosses  representing  the  vines.  The  reader 
will  at  once  notice  that  the  diseased  vines  are  very  scattered,  their 
grouping  very  indefinite,  and  he  would  be  unable  to  tell  from  the  map 
where  the  disease  first  started.  On  the  10th  of  June  there  was  one 
diseased  vine  in  sections  6,  8,  12.  On  the  map,  which  shows  the  posi- 
tion of  the  diseased  vines  on  October  13th,  there  is  not  the  remotest 
suggestion  of  four  centers  of  infection.  From  this  fact  we  may  conclude 
that  priority  of  infection  has  little  to  do  with  the  spread  of  the  Red-leaf 
disease.  And  this  is  the  more  especially  worthy  of  note  since  priority 
of  infection  is  generally  a  most  decided  factor  in  the  spread  of  parasitic 
diseases.  The  reader  has  only  to  recall  to  mind  the  action  of  the 
Phylloxera,  the  Root-rot,  the  Mildew,  etc.  The  parasite  causing  a  given 
disease  may  spread  from  one  plant  to  another  in  a  more  or  less  regular 


OBSERVATIONS   ON    SOME    VINE   DISEASES   IN   SONOMA    COUNTY. 


15 


manner,  which  depends  largely  on  the  nature  of  the  parasite  and  the 
surrounding  conditions.  If  the  parasite  lives  on  the  roots  of  the  plant, 
it  will  spread,  as  it  were,  in  a  circle;  but  if  it  is  a  leaf  parasite,  the  wind, 
all  other  things  being  equal,  will  cause  the  disease  to  spread  with  greater 
rapidity  in  the  direction  in  which  it  blows.  Furthermore,  when  a  plant 
is  preyed  upon  by  some  parasite,  it  shows  all  the  symptoms  character- 
istic of  the  specific  disease,  from  the  minor  to  the  major  in  sequence. 
Now  if  we  apply  these  principles  to  the  study  of  the  Red-leaf  disease, 

Legend: Iron  sulfate  spray. 

Witnesses. 

—  •  —    —  •  —  Bordeaux  mixture. 

Iron  sulfate  and  Bordeaux  mixture. 


12 


11 !. 


July. 


.August 


September.  October, 


FIG.  2.    Progress  of  the  Red-leaf  disease  (in  per  cent)  on  the  South  Sonoma 
Experiment  Plot. 

we  find  that  it  does  not  spread  from  a  center  of  infection.  A  vine  is 
often  diseased  on  a  single  shoot;  it  may  show  the  first  symptoms  of 
disease  in  the  early  summer,  and  never  at  any  other  time.  Some 
healthy  vines  may  in  seven  days  be  affected  in  the  worst  form,  while 
others  have  only  a  cane  or  two,  or  even  only  the  apical  leaves  of  a  few 
shoots,  affected.  These  observations  tend  to  show  that  the  Red-leaf 
disease  is  not  caused  by  a  root  parasite. 

It  remains  to  be  seen  whether  or  not  the  Red-leaf  disease  can  be 
caused  by  a  leaf  parasite.  The  disease  progressed,  the  reader  will  remem- 
ber, from  section  2  toward  section  12  (Fig.  1).  This  progression  was  still 


16  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT   STATION. 

quite  noticeable  in  July.  The  interesting  feature  of  this  progression  is 
the  fact  that  it  was  contrary  to  the  direction  of  the  wind,  which  blew 
daily  across  the  plot  in  the  direction  shown  by  the  arrow.  The  wind 
blew  from  right  to  left;  the  disease  progressed  from  left  to  right;  a  leaf 
parasite  would,  other  things  being  equal,  follow  the  direction  of  the  pre- 
vailing wind.  Furthermore,  the  vines  were,  in  at  least  seven  tenths  of 
the  cases,  more  diseased  to  windward,  notwithstanding  the  Red-leaf 
disease  progressed  against  the  wind.  Again,  the  vines  that  were  some- 
what weakened  by  their  proximity  to  the  eucalypti  (see  shaded  part  of 
map)  and  were  shaded  by  them  in  the  afternoon,  were  barely  touched 
by  the  Red-leaf  disease,  and  that  only  after  the  terrific  hot  weather  in 
September.*  The  leaves  of  these  vines  were  thinner  and  less  consistent 
than  those  of  the  vines  in  constant  sunlight.  They  were  decidedly 
wanting  in  vigor,  and  yet  remained  practically  untouched  by  the 
disease. 

It  seems  difficult  to  reconcile  the  above  facts  with  the  development 
of  a  leaf  parasite.  We  are  more  inclined  to  believe  that  the  Red-leaf 
disease  is  due  to  the  same  causes  as  the  Folletage  and  the  Rougeot, 
namely,  a  disturbance  of  the  equilibrium  between  the  absorption  of 
water  by  the  roots  and  its  transpiration  by  the  leaves. 

The  soil  in  which  the  vineyard  is  planted  is  a  clay  loam  underlaid, 
at  a  depth  of  from  three  to  four  feet,  by  an  impermeable  clay  subsoil, 
at  the  left  of  the  plot;  in  the  middle,  however,  the  soil  is  deeper  and 
the  subsoil  more  permeable;  toward  the  right  the  soil  becomes  deeper 
still  and  more  gravelly  as  one  goes  down.  At  the  end  of  July  there 
was  from  2  to  3  per  cent  of  free  moisture  in  the  soil,  which  is  enough, 
as  the  vines  showed,  to  support  a  good  growth  and  crop  of  fruit,  but 
which  might  easily  become  inadequate  to  supply  the  demands  of  the 
leaves  in  moments  of  great  transpiration  activity. 

Wind,  as  is  well  known,  activates  transpiration  considerably  and., 
under  such  conditions,  might  well  become  the  inciting  cause.  If  we 
take  into  consideration  that  the  vines  were  more  affected  with  the  Red- 
leaf  disease  to  windward,  and  that  the  disease  progressed,  in  the  early 
part  of  the  season  at  least,  from  that  part  of  the  plot  underlaid  by  the 
impermeable  clay  to  that  with  the  freer  subsoil,  we  have  two  facts 
which  bear  out  our  hypothesis  very  well. 

This  hypothesis,  however,  has  against  it  the  results  shown  by  section  3,  which  was 
sprayed  with  the  iron  sulfate  and  the  Bordeaux  mixture.  In  this  section,  at  the  end  of 
the  season,  there  was  not  more  than  ten  per  cent  of  the  vines  diseased,  whereas  in 
the  other  sections  the  percentage  of  diseased  vines  was  almost  double.  From  the 
production  of  the  vines  in  the  different  sections,  we  are  unable  to  gather  any  evidence 
for  or  against  our  hypothesis.  (See  Fig.  3.) 

*This  hot  weather  occurred  on  the  6th,  7th,  and  Sth  of  September,  when  the  ther- 
mometer stood  at  90°  and  105°  F.  in  the  shade. 


OBSERVATIONS    ON    SOME    VINE    DISEASES   IN    SONOMA    COUNTY. 


17 


In  regard  to  the  effect  of  soil  fertility  on  the  Red-leaf  disease,  some 
evidence  well  worthy  of  experimental  control  was  obtained.  In  Sep- 
tember, 1903,  in  a  cursory  examination  of  the  vineyard  in  which  the 
experiment  plot  is  situated,  it  was  noted  that  the  foliage  in  a  "  block  " 
of  old  Mission  vines  which  were  much  larger  and  at  least  ten  years  older 
than  those  in  the  experiment  plot,  showed  very  generally  the  discolora- 
tion of  the  Red-leaf  disease.  These  old  Missions  were  given  a  good  dress- 
ing of  stable  manure  during  the  winter  of  1903.  In  1904  they  were 
kept  more  or  less  under  constant  observation.  On  September  16th  of 
that  year  we  noted  that  the  old  Missions,  which  the  previous  year 
showed  the  foliar  characters  of  the  Red-leaf  disease  so  markedly,  were 
still  healthy. 


r 


TESOJ.VMD  SPOT/HI  rm  rcon  swjwre 


B  -.vine  arwwni  \»ira  HORDE/NX  mxruw 


vires  unrrareo^rai  UTT  K> 
wrnuss. 


,  W,  TrSo   W}     B      W,     Wt    W5     B      W6     B      W, 

FIG.  3.    Table  showing  the  average  production  (in  pounds)  of  the  vines,  both  sprayed 
and  unsprayed,  at  the  South  Sonoma  Experiment  Plot. 

From  these  observations  one  would  surmise  that  fertilizing,  with 
stable  manure  at  least,  would  have  a  certain  action  in  controlling  the 
Red-leaf  disease.  If,  moreover,  coupled  with  these  observations,  it 
were  found  that  the  soil  was  at  all  deficient  in  one  or  all  of  the  plant 
foods,  then  our  surmise  would  become  a  plausibility,  if  not  a  certainty. 
We  had,  therefore,  the  soil  (an  average  sample)  of  our  experiment  plot 
analyzed,  and  with  the  following  result :  The  soil  was  found  to  contain 
less  than  0.05  per  cent  of  phosphoric  acid,  which  is  quite  low  for  a 
productive  soil.  When  we  couple  with  this  deficiency  of  phosphoric 
acid  the  fact  that  the  grapevine  consumes  more  of  this  nutrient  than 
most  fruit  trees,  it  is  not  rash  to  assume  that  fertilization  will  greatly 
help  the  vines  to  at  least  withstand  the  Red-leaf  disease. 


18  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 

THE  GRAPE-SHRIVEL. 

The  disease  that  we  have  denominated  the  Grape-shrivel  is  not  as 
yet,  at  least  so  far  as  known,  of  any  great  economic  importance;  but, 
owing  to  the  circumstances  under  which  it  occurs,  it  is  highly  probable 
that  it  exists  elsewhere  in  the  reconstructed  vineyards  of  California 
and  may,  therefore,  assume,  at  any  moment,  more  than  local  interest. 
The  fact  that  we  observed  the  Grape-shrivel  in  the  East  Sonoma 
experiment  plot,  where  it  took  the  place  of  the  Red-leaf  disease,  is  sug- 
gestive enough,  even  though  it  was  not  observed  at  either  of  the  other 
experiment  plots,  or  in  vineyards  visited. 

Description  of  the  Grape-Shrivel. — The  Grape-shrivel,  as  its  name 
implies,  is  characterized  by  the  shriveling  of  the  berries.  In  fact,  this 
shriveling  is  the  only  diagnostic  character  of  this  disease,  the  symptoms 
which  appear  in  the  leaves  being  easily  referable  to  drought,  or  imper- 
fect nutrition. 

The  Grape-shrivel  develops  quite  rapidly,  as  shown  by  the  fact  that 
while  no  symptoms  of  the  disease  were  observed  on  the  27th  of  June, 
yet  on  the  12th  of  July  many  vines  were  affected.  By  the  end  of  July 
practically  every  vine  in  the  experiment  plot  showed  the  characteristic 
shriveled  grapes  of  this  disease. 

The  distribution  of  the  Grape-shrivel  is  at  first  somewhat  irregu- 
lar, then  general.  The  grapes  on  weak  vines  (not  necessarily  dying 
vines)  and  strong  vines  are  equally  affected.  The  fruit  on  weak  shoots 
and  strong  shoots  is  affected  alike.  The  general  health  of  the  vine 
seems  to  bear  no  relation  whatever  to  the  distribution  and  intensity 
of  the  disease.  Vigorous,  weakly  arid  dying  vines  (all  with  affected 
grapes)  commingle ;  there  are  not  the  usual  regular,  or  semi-regular, 
depressed  areas  of  vegetation  so  characteristic  of  parasitic  diseases. 

Effect  of  the  Disease  on  the  Grapes. — The  Grape-shrivel,  as  already 
mentioned,  is  characterized  by  its  effect  upon  the  fruit.  The  berries* 
lose  their  clear,  turgid  appearance  and  become  dull  and  flabby  (but 
never  blotched,  as  in  the  Red-leaf  disease),  irregularly  wrinkled  and, 
as  it  were,  thick-skinned;  as  the  drying  progresses  the  wrinkling 
becomes  more  pronounced  and  assumes  a  direction  more  nearly  parallel 
to  the  axis  of  the  berry  (Fig.  4).  When  completely  dry  the  berries  are 
uniformly  bluish,  in  some  cases,  where  exposed  to  the  sun,  washed 
with  red;  they  are  tightly  shrunken  around  the  seeds,  and  coriaceous. 
At  this  stage  the  pedicels  and  the  peduncle,  to  within  a  short  distance 
of  the  cane,  are  dried  and  discolored;  the  green  and  dried  portions  of 
the  peduncle  become  severed,  and  the  completely  desiccated  bunch  of 

*As  we  have  only  observed  the  Grape-shrivel  on  one  variety  of  white  grape  (the 
Sernillon)  the  description  of  the  effect  of  the  disease  on  the  berries  can  only  apply 
integrally  to  varieties  of  the  grapevine  producing  white  fruit. 


OBSERVATIONS    ON    SOME   VINE   DISEASES   IN    SONOMA    COUNTY. 


19 


grapes  falls  to  the  ground.  Such  is  the  progression  of  the  disease  in 
the  grapes  while  they  are  still  green,  but,  when  they  begin  to  mature 
the  shrinkage  becomes  less  total  as  the  absolute  percentage  of  sugar 
increases  in  the  fruit. 

The  fruit  of  diseased  vines,  when  it  does  not  shrivel,  often  ripens 
prematurely.  This  prematurely  ripened  fruit  is  frequently  edible, 
though  sometimes  quite  distasteful. 

The  manner  in  which  the  malady  works  on  the  different  bunches  of 
the  same  cane  is  quite  characteristic.  The  lower  bunch  of  grapes  is  the 


FIG.  4.    Bunches  of  grapes  showing  progress  of  Grape-shrivel. 

first  to  show  signs  of  the  disease;  it  is  not  rare  for  one  to  find  the  lowest 
bunch  much  diseased,  and  the  upper  just  beginning  to  show  the  first 
nigns.  We  have  even  found,  on  canes  bearing  three  bunches  of  grapes, 
the  first  bunch  completely  desiccated,  the  second  shriveled,  and  the 
third  absolutely  sound.  There  are  canes,  however,  in  which  the  differ- 
ences are  less  marked,  and  some  even  in  which  the  progression  of  the 
disease  is  reversed. 

Effect  of  the  Disease  on  the  Leaves. — The  disease  does  not  show  in  the 
foliage  at  first.  The  leaves  of  strong,  healthy  vines  and  strong,  healthy 
shoots  remain  turgid  and  green;  the  leaves  of  weaker  vines  and  weaker 


20  UNIVERSITY    OF   CALIFORNIA — EXPERIMENT   STATION. 

shoots  may  be  somewhat  faded  and  yellow.  The  yellow  coloration  may 
be  total  or  partial,  and  the  leaves  irregularly  dry  in  those  parts  of  the 
parenchyma  longest  deprived  of  chlorophyll,  that  is  from  the  edges 
inward.  The  lower  leaves  are  more  affected  than  the  upper. 

Following  the  shriveling  of  the  grapes,  the  foliage  of  the  more  vigor- 
ous vines,  after  a  longer  or  shorter  time,  begins  to  show  the  same  char- 
acters that  the  leaves  of  the  weaker  vines  assume  at  an  earlier  period. 
These  characteristics  are  illustrated  in  the  accompanying  colored 
figures  on  Plate  I.  The  chlorophyll  becomes  resorbed  at  the  edge  of 
the  leaf  (Plate  I,  Fig.  7),  which  yellows;  this  resorption  may  continue 
until  the  whole  of  the  leaf  is  bright  yellow  (Plate  I,  Fig.  1). 
Following  this  stage,  which  is  not  infrequent  in  the  basal  leaves,  the 
leaf  either  dries  up  completely  and  at  once  (Plate  I,  Fig.  3),  or,  as  occurs 
more  often,  from  the  periphery  inward,  with  a  slight  rolling  of  the  edges 
(Plate  I,  Fig.  2).  In  other  cases,  however,  the  entire  blade  of  the  leaf 
does  not  become  so  regularly  yellow  and  then  dry.  Indeed,  one  fre- 
quently observes  the  yellowing  at  first  confined  to  the  apical  lobe  (Plate 
I,  Fig.  4),  and  then  gradually  progressing  toward  the  petiole  (Plate  I, 
Fig.  5),  the  wings  of  the  leaf  remaining  the  while  of  a  sub-healthy  green. 
The  chlorotic  tissue  gradually  dries,  sometimes  irregularly,  but  not 
infrequently  in  a  very  regular  manner  (Plate  I,  Fig.  6).  As  soon  as 
the  center  portion  of  the  leaf  has  dried,  the  wings  of  the  leaf  die.  Fig.  6 
represents  a  leaf,  the  center  of  which  became  chlorotic  and  then  dried 
up;  the  death  of  the  entire  leaf  then  followed. 

A  leaf  presenting  the  characters  of  that  illustrated  in  Fig.  8  is  more 
exceptional.  In  this  leaf  the  greater  part  of  the  leaf-blade  was  sud- 
denly killed  without  previous  yellowing  or  chlorophyll  resorption.  The 
dead  tissue,  it  will  be  observed,  has  a  shade  of  green  in  it,  whereas  in 
all  the  other  diseased  leaves  it  is  fawn-colored  or  brown.  If  the  reader 
will  imagine  the  dead  tissue  (Fig.  8)  colored  brown  instead  of  greenish- 
fawn,  he  will  have  the  representative  of  a  leaf  that  was  chlorotic  around 
the  edges  and  in  the  greater  part  of  the  blade.  This  chlorosis,  however, 
did  not  spread,  and  the  affected  tissue  rapidly  died  without  impairing 
the  functions  of  the  remaining  healthy  portion  of  the  leaf. 

Internal  Appearance  of  the  Shoots,  Spurs,  Arms,  and  Body  of  Vines. — 
The  spurs,  the  arms,  and  the  body  of  the  vine  show  no  outward  signs  of 
disease  at  all.  The  shoots  mature  sometimes  very  unevenly,  but  this 
characteristic  is  unimportant.  The  shoots,  spurs,  and  body  of  the  vine 
show,  however,  certain  internal  symptoms  which  should  be  noted. 

Cross  and  longitudinal  sections  of  the  shoots,  spurs,  arms,  and  body 
of  the  vine  show  discolorations  in  the  wood  and  pith.  In  the  shoots  a 
slight  discoloration  of  the  woody  tissue  next  the  pith  can  be  traced  with 
comparative  ease  at  least  as  far  as  the  last  bunch  of  grapes  showing 
shriveling;  but  the  brown  discolorations  in  the  pith  are  not  so  constant: 


OBSERVATIONS   ON   SOME   VINE   DISEASES   IN   SONOMA   COUNTY.  21 

now  and  then  they  may  occur  just  above  and  below  the  diaphragms, 
and  without  regularity;  at  other  times  a  slight  discoloration  of  the  pith 
may  be  traced  from  the  base  of  the  shoot  up  several  nodps.  In  the 
spurs  the  woody  tissue  of  the  previous  year  is  brown  and  often,  more 
especially  near  the  edge,  zoned  with  darker  lines.  In  the  arms  we  have 
the  same  general  appearance  as  in  the  spurs,  with  this  difference  that, 
in  cross-section,  the  darker  areas  may  be  more  suffused.  In  the  trunk 
the  discolorations  of  the  wood  are  less  pronounced  and,  in  longitudinal 
section,  appear  as  striations  which  become  less  numerous  as  one  nears 
the  stock  (the  diseased  vines  are  grafted  on  Lenoir),  which  they  rarely 
penetrate  to  any  extent;  or,  if  no  decay  or  dead  tissue  is  present,  the 
live  wood  may  be  suffused  with  a  faint  brown  tinge,  from  which  the 
striations  stand  out  less  boldly.  The  bodies  of  the  vines  have,  however, 
in  most  cases  suffered  more  extended  disorganization  than  just  described. 
One  finds,  whenever  large  limbs  have  been  at  one  time  removed,  decay 
and  dead  tissues  occupying  a  large  part  of  the  body  of  the  vine  and 
eating  gradually  down  toward  the  stock,  which  is  rarely  affected,  how- 
ever, to  any  serious  extent. 

The  roots  are  always  healthy,  even  in  sickly  vines. 

Generalities  regarding  the  Work  at  the  East  Sonoma  Experiment  Plot. — 
This  plot  was  established  in  a  vineyard  reconstituted  some  twenty  years 
ago.  Lenoir  was  the  grafting  stock  originally  used;  but  from  time  to 
time,  as  vacancies  occurred,  other  stocks — mostly  Rupestris  of  the  Fort 
Worth  type — were  used  to  fill  in  the  missing  places.  In  that  part  of 
the  vineyard  selected  for  the  experiment  plot  (the  only  really  diseased 
portion)  the  Lenoirs  are  carrying  Semillon  grafts. 

The  plot,  however,  is  not  free  from  admixture.  A  few  Zinfandels  are  scattered  here  and 
there  and  were  evidently  accidentally  introduced  when  refilling  the  vacancies.  When  the 
vineyard  was  reconstituted  the  grafting  was  well  done  and  the  grafts  were  not  allowed 
to  strike  root.  Furthermore,  there  was  never  any  great  disparity  of  growth  between 
the  stock  and  graft,  and  consequently  the  unions  are  smooth.  The  vines  were  pruned 
short  prior  to  1902,  and,  in  consequence,  had  never  produced  much  of  a  crop,,  the 
Semillon  being  one  of  the  grapes  that  demands  long  pruning  to  produce  fully.  The 
vines,  however,  under,  this  regime,  were  moderately  healthy  and  sufficiently  vigorous. 
In  1902  the  system  of  pruning  was  changed  from  short  to  long.  Following  the  adop- 
tion of  the  long  pruning  the  vines  began  to  show  disease.  In  1903  they  were  already 
much  affected.  This  new  disease  was  then  supposed  to  be  the  Red-leaf  disease.  We 
now  know  that  it  was  the  Grape-shrivel. 

Acting  on  the  assumption  that  the  disease  in  this  vineyard  was  the 
Red-leaf,  arrangements  were  made  in  February,  1904,  to  carry  out  there 
the  same  spraying  experiments  as  at  the  other  two  plots.  The  East 
Sonoma  plot  was  divided  into  twelve  sections,  containing  four  rows  of 
vines  each.  Sections  1  and  7  were  sprayed  with  acid  iron  sulfate,  * 
sections  3  and  9  with  acid  iron  sulfate  and  Bordeaux  mixture;  sections 
2,  4,  6,  and  12  were  left  as  witnesses.  Sections  1,  3,  7,  and  9  were 

*For  the  method  of  preparing  this  fungicide,  see  page  12. 


22  UNIVERSITY    OF   CALIFORNIA EXPERIMENT   STATION. 

sprayed  with  the  acid  iron  sulfate  on  the  28th  of  March,  just  as  the 
buds  were  beginning  to  swell.  Sections  3,  5,  9,  and  11  were  sprayed 
with  Bordeaux  mixture  (4  pounds  of  copper  sulfate,  4  pounds  of  lime, 
40  gallons  of  water)  011  the  6th  and  26th  of  May,  and  the  16th  of  June. 

The  growth  of  the  vines  on  the  sprayed  and  unsprayed  rows  was 
sporadic  and  uneven.  After  the  second  spraying  with  Bordeaux  mixture 
the  foliage  of  the  sprayed  vines  was  somewhat  greener  than  that  of  the 
witnesses.  By  the  16th  of  June,  the  date  of  the  third  spraying  with  the 
Bordeaux  mixture,  no  specific  signs  of  disease  had  shown  in  either  the 
witnesses  or  the  treated  vines,  other  than  such  as  might  be  referred  to 
known  causes.  The  appearance  of  the  plot  was  in  no  way  such  as  to 
create  a  fear  that  the  vines  would  collapse  and  fail  to  ripen  their  fruit. 
On  the  27th  of  June  the  general  appearance  of  the  vines  was  somewhat 
wan,  and  the  line  of  demarkation  between  the  sprayed  and  unsprayed 
vines  had  well-nigh  ceased  to  exist.  On  the  12th  of  July,  however, 
almost  every  vine  in  the  plot  showed  unmistakable  signs  of  suffering; 
the  foliage  was  pale,  and  many  clusters  of  grapes  had  already  shriveled, 
or  were  just  beginning  to  collapse;  there  was  no  longer  any  difference 
between  the  witnesses  and  the  sprayed  vines.  In  fact,  so  general  were 
the  symptoms  of  disease  in  both  the  treated  and  untreated  vines  that 
any  further  attempt  to  check  it  with  Bordeaux  mixture  was  given  up  as 
useless.  By  the  end  of  July  practically  every  vine  in  the  experiment 
plot  was  affected  with  the  Grape-shrivel,  with  the  exception  of  the  Zin- 
fandels  and  the  non-grafted  Lenoirs. 

On  the  21st  of  July,  when  well-nigh  every  vine  in  the  plot  was  affected 
with  the  Grape-shrivel,  the  free  moisture  in  the  soil,  a  loam  underlaid 
at  the  depth  of  two  feet  with  a  gravelly  clay-subsoil,  varied  between 
nine  and  ten  per  cent. 

The  roots  of  the  stock  in  different  parts  of  the  plot  were  examined 
from  time  to  time  for  the  purpose  of  determining  their  resistance  to  the 
Phylloxera.  Nodosities  were  always  found  to  be  present  in  plenty,  both 
on  the  grafted  and  on  the  non-grafted  Lenoirs. 

At  the  end  of  July  one  per  cent  of  the  vines  in  the  experiment  plot 
were  dug  up,  split  open  and  examined.  The  result  of  this  examination 
is  given  on  page  20,  where  the  internal  appearance  of  the  shoots,  spurs, 
and  body  of  vines  affected  with  the  Grape-shrivel  is  described. 

In  the  beginning  of  August  a  critical  examination  was  made  of  the 
vines  in  the  plot,  for  the  purpose  of  determining  if  there  was  any  rela- 
tion between  the  vigor  of  the  vine  or  of  any  of  its  individual  shoots, 
and  the  Grape-shrivel.  The  only  fact  this  examination  clearly  revealed 
was  that  the  vines  had  been  given  too  liberal  a  pruning.  In  general, 
no  more  than  half  the  eyes  left  at  pruning  time  had  sprouted,  and 
sometimes  less. 

The  yield  of  the  experiment  plot  (one  acre)  was  about  700  pounds  of 


OBSERVATIONS   ON   SOME   VINE   DISEASES   IN   SONOMA   COUNTY.  23 

grapes.     The  Grape-shrivel  had  destroyed  the  four  or  five  tons  of  fruit 
that  the  showing  of  the  vines  in  June  would  have  led  one  to  expect. 

Cause  of  the  Grape-shrivel. — From  the  description  of  the  Grape-shrivel, 
and  the  manner  and  circumstances  under  which  it  develops,  it  is  evident 
that  the  disease  is  a  peculiar  manifestation  of  imperfect  nutrition.  The 
yellowing  and  dying  of  the  leaves,  beginning  at  the  base  of  the  shoots, 
is  characteristic  of  vines  suffering  from  want  of  water.  Premature 
ripening  is  also  a  consequence  of  lack  of  water.  The  fact  that  the 
grapes  shrivel,  often  previously  to  the  discoloration  and  wilting  of  the 
foliage,  does  not  invalidate  this  contention;  for,  it  may  be  shown  that 
under  the  influence  of  drought,  or  a  paucity  of  free  water  in  the  soil,  the 
fruit  of  the  French  prune  will  shrivel  even  when  the  foliage  is  healthy 
and  luxuriant.  It  is,  therefore,  no  stretch  of  the  imagination  to  suppose 
that  the  same  phenomenon  happens  in  the  case  of  the  vine.  In  fact,  in 
several  cases  we  have  obtained  experimentally  the  characteristics  of  the 
Grape-shrivel  as  shown  in  the  grapes.  Our  experiments,  though  crude 
enough,  were  quite  instructive.  We  severed,  in  healthy  vines,  several 
long  canes  bearing  vigorous  shoots  carrying  well-developed  bunches  of 
grapes.  Almost  immediately  after  the  canes  were  severed  the  shoots 
began  to  wilt,  as  one  would  expect.  The  bunches  of  grapes,  however, 
generally  wilted  as  they  do  in  the  case  of  the  Grape-shrivel:  the  lower 
bunches  on  a  shoot  would  frequently  dry  out  faster  than  the  others. 
We  also  observed  that  the  pith  discolored  in  the  neighborhood  of  the 
diaphragms  first,  and  that  the  wood  tissue  became  discolored. 

The  discoloration  of  the  pith  in  the  shoots,  and  the  discolorations  in 
the  spurs,  arms,  and  trunk,  may  be  shown  to  occur  in  vines  under  very 
varied  and  divers  circumstances,  and  are,  therefore,  at  most  of  but 
secondary  importance. 

The  symptoms  of  the  Grape-shrivel,  then,  are  those  of  a  vine  suffering 
from  drought.  This  is  further  emphasized  by  the  following  facts: 

The  Lenoir,  the  stock  upon  which  the  Semillons  are  grafted,  is  not 
very  resistant  to  the  Phylloxera.  Its  rootlets  (which,  the  reader  will 
bear  in  mind,  are  the  active  agents  in  the  absorption  of  water)  were 
much  distorted  by  the  Phylloxera,  and  their  functions,  therefore,  inter- 
fered with.  This  fact  explains  how  it  is  that  a  vine  grafted  on  Lenoir 
(or  any  other  stock  sensitive  to  the  Phylloxera)  could  suffer  from  want 
of  water,  even  when  the  soil  contained  nine  or  ten  per  cent  of  free 
moisture.  But  it  may  be  asked,  why  does  the  non-grafted  Lenoir  not 
suffer  ?  This  question  is  easily  answered.  The  Lenoir  is  not  as  vigor- 
ous a  grower  nor  as  heavy  a  bearer  as  the  Semillon.  When  it  bears 
the  Semillon,  then,  or  any  other  vinifera  more  vigorous  than  itself,  its 
rootlets,  even  when  not  preyed  upon  by  the  Phylloxera,  are  unable  to 
take  up  and  transfer  to  the  graft  its  optimum  of  food;  and  the  bigger 


24  UNIVERSITY    OF   CALIFORNIA  — EXPERIMENT    STATION. 

and  finer  the  graft  the  greater  the  difficulty  the  Lenoir  has  in  supply- 
ing it  with  its  full  quota  of  nutriment. 

But  if  the  rootlets  of  the  Lenoir  are  much  damaged  by  the  Phylloxera, 
the  equilibrium  can  not  be  maintained  and  the  graft  will  show  signs  of 
distress.  Why,  then,  have  the  vines  at  the  East  Sonoma  experiment 
plot  lived  so  long  ?  The  answer  to  this  question  is,  that  the  vines  were 
formerly  short-pruned  and  were  unproductive,  but  that  since  1902  they 
have  been  long-pruned  and  made  to  produce  largely. 

In  the  first  case  the  equilibrium  between  the  stock  and  the  graft  was 
practically  maintained;  in  the  latter,  it  was  destroyed.  It  must  not  be 
forgotten,  however,  that  the  Phylloxera  is  in  a  measure  an  active  agent 
in  causing  the  Grape-shrivel,  and  that  the  severity  of  the  disease  during 
1903  and  1904  may  be  due  to  circumstances  favoring  the  development 
of  this  pest. 

In  combatting  the  Grape-shrivel  on  grafted  vines,  two  things  must  be 
taken  into  account:  First,  the  affinity  between  the  stock  and  the  graft; 
second,  the  resistance  of  the  stock  to  the  Phylloxera. 

The  affinity  (and  by  affinity  we  mean  all  the  necessaries  to  a  con- 
joint life)  between  stock  and  scion  is  to  be  maintained  in  equilibrium 
by  judicious  pruning,  supplemented  by  thorough  fertilization. 

The  resistance  of  the  stock  to  the  Phylloxera  will  be  indirectly 
heightened  by  fertilization;  but  if  then  found  to  be  insufficient,  it 
should  be  changed  for  a  more  resistant  one.  The  use  of  bisulfid 
of  carbon,  in  protecting  stocks  of  low  resistance  from  the  attacks  of 
Phylloxera,  is  not  at  present  an  economic  possibility. 


ROOT-ROT.* 

The  action  of  this  disease  in  its  main  characteristics  is  very  similar 
to  the  malady  known  among  the  French  as  the  Pourridie,  or  Blanc  des 
racines,  and  in  Germany,  according  to  Mr.  P.  Viala,f  by  the  name  of 
Weinstock-faule.  The  areas  of  depressed  vegetation  that  one  associates 
familiarly  with  the  action  of  the  Phylloxera,  are  characteristic  also  of 
the  Root-rot.  In  each  case  there  is  a  center  of  infection,  though,  when 
compared  with  the  Phylloxera,  the  Root-rot  spreads  more  slowly  and 
appears  circumscribed  or  local  in  its  action.  In  the  case  of  the  Root- 
rot  there  may  occur  many  small  centers  of  infection  in  close  proximity 
to  one  another  which  may  take  several  years  to  merge  into  one;  whereas, 
in  the  case  of  the  Phylloxera,  when  infection  is  so  general  that  several 
centers  start  very  near  one  another,  they  rapidly  become  one. 

*  These  remarks  of  Mr.  Butler  on  the  Root-rot  are  of  very  great  importance  at  the 
present  time,  as  this  disease  is  doing  a  great  deal  of  damage  in  certain  parts  of  Santa 
Clara,  Sacramento,  and  San  Joaquin  valleys.  In  some  districts  the  Root-rot  is  far  more 
destructive  than  the  Phylloxera.  <(E.  H.  T.) 

t  P.  Viala:  "Les  Maladies  de  la  Vigne,"  3d  ed.,  page  248. 


OBSERVATIONS    ON    SOME    VINE    DISEASES   IN    SONOMA    COUNTY.  25 

The  Root-rot  is  caused  by  a  fungus, — possibly  several,  fungi,—  and  in 
its  usual  form  is  very  easily  recognized  upon  digging  up  any  vine 
within  an  infected  area.  The  roots  are  soft,  watery,  yellowish-brown 
in  the  entire  woody  cylinder,  and  more  or  less  permeated  with  whitish 
threads — the  mycelium  of  the  parasite — and  give  off  a  strong  nauseous 
fungous  odor.  As  the  lower  roots  are  destroyed,  and  the  mortification 
enters  the  body  of  the  vine  and  slowly  eats  its  way  in  the  trunk  to  the 
surface  of  the  soil,  and  even  above,  new  roots  are  sent  out  from  the  still 
healthy  encompassing  tissue;  these  roots,  in  turn,  become  riddled  with, 
and  succumb  to  the  attacks  of  the  fungus.  In  the  last  stages  of  the 
disease  (that  is,  when  the  vine  has  sent  out  a  few  feeble  canes  about  a 
foot  long)  one  invariably  finds  near  or  at  the  surface  of  the  soil,  a  very 
free  growth  of  young  tender  roots. 

Though  the  Root-rot  is  generally  of  the  form  just  described,  and  takes 
from  two  to  five  years  to  kill  the  vine,  it  may,  in  some  rare  cases  and  in 
young  vineyards,  spread  with  such  rapidity  that  it  kills  the  vines  in 
eighteen  months,  and  even  in  a  single  season.  Mr.  P.  Viala  observes: 
"The  vines  may  succumb  in  from  fifteen  to  eighteen  months,"  and  that 
he  "has  even  caused  their  death  in  six  months  by  placing  them  under 
the  most  favorable  conditions  for  the  development  of  the  Pourridie."  * 

The  author  observed,  during  the  summer  of  1904,  in  a  young  vine- 
yard, a  remarkably  intense  and  destructive  attack  of  Root-rot,  which,  in 
many  instances,  had  gained  an  entrance  into  the  vines  during  the  late 
spring  or  early  summer,  and  had  practically  ruined  the  greater  part  of 
them  by  October.  Many  there  were  that  would  not  "come  out"  in  the 
spring,  or,  if  they  did,  would  die  during  the  summer. 

The  growth  of  vines  affected  with  the  usual  form  of  Root-rot  resembles 
that  of  vines  affected  with  the  Phylloxera.  Their  growth  gradually 
becomes  weaker  and  weaker,  and  the  vines  finally  die.  But  in  the  rapid 
form  of  this  disease  there  is  no  such  gradual  wasting  away.  The  foliage 
of  the  vines  becomes  chlorotic,  and,  if  the  weather  is  at  all  unfavorable, 
rapidly  sears  and  falls  off.  The  blade  of  the  leaf  not  infrequently  sep- 
arates from  the  petiole,  which  remains  a  while  longer  attached  to  the 
shoots.  The  maturity  of  the  shoots  is  impeded;  their  lignification  is 
imperfect,  irregular,  and  at  times  resembles  that  which  has  come  to  be 
considered  typical  of  the  Anaheim  disease;  in  other  words,  strips  on 
elongate  spots  of  immature  tissue  may  be  found  in  the  midst  of  mature 
wood.  The  fruit  matures  imperfectly.  The  photograph  of  the  vine 
shown  in  Fig.  5  was  taken  early  in  October,  and  shows  the  general  appear- 
ance of  a  young  vine  affected  with  the  rapid  form  of  the  Root-rot.  The 
vine  was  evidently  not  affected  with  this  disease,  if  we  may  judge  from 
its  growth,  until  late  in  spring. 

The  appearance  of  the  diseased  vines  below  ground  is  necessarily 
different  from  that  of  those  affected  with  the  milder  form  of  the  Root- 
*P.  Viala:  "Monographic  du  Pourridie,"  Introduction. 


26 


UNIVERSITY    OF   CALIFORNIA — EXPERIMENT   STATION. 


rot.  Instead  of  the  entire  underground  portions  being  soft,  watery, 
and  decayed,  the  woody  cylinder  suffers  no  outward  disorganization, 
but  is  more  or  less  discolored  according  as  it  is  examined  nearer  to  or 
farther  from  the  original  center  of  infection.  In  fact,  so  slight  is  the 


FIG.  5.    Young  vine  killed  by  Root-rot. 


decay  of  the  tissues  that  a  vine,  when  cursorily  examined  after  it  has 
been  dug  out,  shows  no  signs  of  a  specific  disease.  The  bark  on  the  stem 
is  tight  and  dry,  and  is  not  suggestive  ;  on  the  roots  it  is  often  streaked 
with  filmy  white,  but  even  this  is  not  characteristic  enough  to  hold 


OBSERVATIONS   ON   SOME   VINE   DISEASES   IN   SONOMA   COUNTY.  27 

one's  attention.  But  when  one  examines  a  diseased  vine  a  little  more 
closely  he  discovers  that  it  gives  off  the  nauseous  fungous  odor  so 
characteristic  of  the  Root-rot,  and  that  a  cross-section  through  the 
stem  or  roots  shows,  between  the  wood  and  the  bark,  a  dirty  white  sub- 
continuous  line,  which  is  not  very  distinct  and  is  easily  overlooked. 
If,  however,  a  piece  of  the  bark  is  cut  off,  there  will  appear  between  it 
and  the  woody  cylinder  a  white,  or  grayish  felt-like,  mass  of  interwoven 
threads — the  mycelium  of  the  Root-rot  fungus.  The  vine  shown  in 
Fig.  5  was  one  mass  of  this  fungous  growth  to  within  an  inch  or  so  of 
the  surface  of  the  soil. 

The  vineyard  in  which  the  exceptionally  severe  form  of  Root-rot  just 
described  was  observed  had  been  established  in  1902,  on  land  that  had 
been  cleared  during  the  year  1900.  The  piece  of  land  on  which  the 
vineyard  is  planted  lies  on  the  sunny  slope  of  a  fairly  steep  range  of 
hills.  This  slope  in  profile  might  be  likened  to  an  S  reversed  and  con- 
siderably drawn  out  lengthwise,  and  lying  at  an  angle  of  about  thirty 
degrees  with  the  horizontal.  The  soils  in  this  piece  of  land  are  both 
poor  and  good.  Beginning  at  the  bottom,  and  extending  up  the  slope 
some  one  hundred  feet,  we  find  a  very  shallow  sandy  soil,  inclined  to  be 
compact  and  hard,  and  underlaid,  at  a  depth  of  a  foot  or  more,  with  a 
clayey  subsoil.  This  soil  becomes  very  wet  in  winter.  On  the  remain- 
der of  the  slope  the  soil  is  friable,  inclined  to  red,  fertile,  and  with  the 
subsoil  considerably  below  the  surface.  In  this  soil  the  vines  may  be 
completely  dug  out  with  a  spade,  whereas  a  mattock,  and  a  good  one,  is 
needed  to  remove  the  vines  from  the  soil  at  the  bottom  of  the  hill.  The 
growth  of  oaks,  before  the  land  was  cleared,  was  meager  at  the  bottom 
of  the  slope,  on  the  refractory  soil,  but  quite  dense  everywhere  else.  A 
year  after  the  land  was  cleared  the  vines  were  planted.  They  were 
Carignanes  grafted  on  resistant  stocks.  On  the  light,  friable  soil  the 
Rupestris  St.  George  was  the  stock  employed;  whereas  on  the  refractory 
soil  at  the  bottom  of  the  hill,  Rupestris  of  the  Fort  Worth  type  appears 
to  have  been  exclusively  used.  The  former  were  more  vigorous  than 
the  latter. 

These  being  the  facts  one  would  naturally  expect  the  Root-rot  to 
develop  first  among  the  Fort  Worth  Rupestris,  and  spread  from  these 
to  the  Rupestris  St.  George.  This  would  certainly  have  been  more  in 
accord  with  the  general  behavior  of  Root-rot  fungi.  The  reverse  was 
true,  however;  the  Rupestris  St.  George  and  not  the  Fort  Worth 
Rupestris  were  the  vines  affected. 

But  with  the  Root-rots,  like  with  many  other  parasites  of  both  the 
vegetable  and  animal  kingdoms,  the  usual  areas  of  adaptability,  when 
one  or  more  conditions  are  particularly  favorable,  may  be  passed  over. 
In  fact,  it  is  well  known  that  in  the  case  of  the  Root-rot,  though 
usually  serious  only  in  wet  soils,  it  may  spread  in  comparatively  dry 


28  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 

soils  if  the  plants  growing  in  said  soils  happen  to  be  sensitive  to  the 
disease,  and  climatic  conditions — a  wet  Avinter,  for  instance — -are 
favorable. 

In  the  case  of  the  rapid  form  of  the  Root-rot  affecting  the  young 
vineyard  above  mentioned,  we  know  that  the  land  was  full  of  decaying 
roots  and  other  debris  from  the  oaks  that  had  been  grubbed  out;  we 
also  know  that  Rupestris  St.  George  is  very  sensitive  to  this  disease, 
and,  furthermore,  that  the  latter  part  of  last  winter  was  wetter  than 
usual. 

The  intensive  and  rapid  growth  of  the  Root-rot  in  a  three-year-old 
vineyard  grafted  on  Rupestris  St.  George,  and  established  in  a  soil 
which,  from  its  situation  and  friability,  would  be  considered  unfavor- 
able to  the  development  of  the  parasite,  is  beyond  a  doubt  exceptional. 
However,  this  particular  case  has  been  dwelt  upon,  less  on  account  of 
its  economic  importance  than  for  the  fact  that  it  demonstrates  very 
conclusively  the  sensitiveness  of  the  Rupestris  St.  George  to  Root-rot,  a 
point  which  we  shall  have  occasion  to  dwell  upon  again. 

Vines  affected  with  the  rapid  form  of  the  Root-rot  can  not,  of  course, 
be  saved.  Vines  affected  with  the  usual  form  are,  when  treate'd  before 
the  disease  has  made  much  progress,  amenable  to  treatment.  The  pre- 
ventive treatment  here  recommended  applies  equally  well  to  both  forms 
of  Root-rot. 

The  remedial  or  preventive  measures  used  in  combatting  the  Root-rot, 
or  indeed  any  other  disease  attacking  the  subterranean  organs  of  plants, 
are,  at  best,  but  palliatives.  As  the  disease  is  more  general  in  soils  with 
an  impermeable  substratum  that  are  quite  retentive  and  miry  after 
heavy  rains,  adequate  drainage  is  and  will  always  remain  the  only 
valuable  preventive  and  curative  measure.  For  excessive  humidity  is 
the  exciting  cause  of  the  disease;  it  favors  fungous  development,  and  the 
tissues  of  the  roots  are  soft,  gorged  with  water,  and  in  no  condition  to 
resist  the  attacks  of  parasites.  An  author  (Mr.  P.  Viala*)  who  has 
studied  the  Pourridie  of  the  vine  and  fruit  trees  with  particular  care, 
says:  "One  must,  to  prevent  the  disease  from  spreading,  and  to  protect 
one's  self  against  it  in  new  plantations,  thoroughly  drain  the  soils  in  which 
it  exists,  and  also  those  that  are,  through  their  retentiveness,  favorable 
to  its  development."  "Drainage  is  an  excellent  preventive  measure," 
he  continues,  "and  what  is  more,  the  only  efficacious  one."  But  as 
drainage  is  not  always  economically  possible,  a  few  half  measures  that 
are  at  least  useful  may  be  mentioned,  even  if  they  have  not  the  virtue 
of  an  elixir. 

As  soon  as  the  disease  shows  in  the  vineyard,  all  badly  diseased  vines 
(that  is,  those  vines  whose  scant  growth  shows  that  their  main  root- 
system  is  seriously  attacked)  should  be  removed  and  the  vines  surround- 

*Loc.  cit.,  page  248. 


OBSERVATIONS   ON   SOME   VINE .  DISEASES   IN   SONOMA   COUNTY.  29 

ing  them  treated  with  a  three  per  cent  solution  of  blue  vitriol*  or  a 
seven  per  cent  solution  of  green  vitriol. f  This  is  done  by  digging  with 
a  hoe  a  small  basin  around  the  trunk  of  the  vines  and  pouring  into  it  a 
gallon  or  so  of  either  solution,  the  quantity  being  determined  by  the 
nature  of  the  soil  and  the  supposed  extent  of  the  root-system.  If  for 
any  reason  it  is  inconvenient  to  treat  the  vines  with  either  of  the  vitriol 
solutions,  a  pound  of  either  the  bluestone  or  the  copperas  may  be  placed 
around  the  trunks  and  allowed  to  dissolve  in  the  winter  rains;  but  this 
method  will  not  be  as  effective.  Before  replanting  the  areas  destroyed 
by  the  rot,  the  holes  destined  to  receive  the  young  vines  should  be 
partly  filled  with  either  blue  or  green  vitriol  solution,  and  then,  when 
the  fungicide  has  soaked  away,  planted.  In  soils  that  are  subject  to 
the  Root-rot,  rooted  vines  should  always  be  planted,  and  as  shallowly 
as  cultivation  will  permit.  Cuttings  should  never  be  used,  for  they  have 
to  be  planted  deeper  than  rooted  vines,  the  chances  of  infection, 
especially  on  the  cut  surface,  being  thereby  increased. 

Vineyards  that  have  once  been  infected  with  the  Root-rot  are,  unless 
drained,  always  subject  to  it;  therefore,  it  is  essential  that  those  parts 
that  have  been  destroyed  by  this  disease  should,  when  replanted,  be 
treated  every  two  or  three  years  by  one  of  the  methods  above  outlined. 

The  Root-rot  attacks  not  only  the  common  grapevine  (  Vitis  vinifera), 
but  probably  also  more  or  less  severely  the  different  resistant  stocks. 
The  Rupestris  St.  "George  is  very  sensitive  to  it;  but  according  to  Mr. 
Jallabert,J  whose  demonstration  is  quite  convincing,  the  Riparia  X 
Rupestris  3306  is  almost  immune.  He  planted  the  latter  in  a  soil 
infected  with  the  Pourridie  and  which,  even  in  the  dog  days,  could  only 
be  worked  to  a  depth  of  six  inches.  "Somewhat  below  this  the  clay 
was  saturated,  and,  lower  down,  mud."§  In  such  a  soil  as  this,  and 
despite  the  Pourridie,  the  3306  flourished.  We  may  feel  confident,  then, 
that  wherever  the  Root-rot  is  bad  in  California,  the  Riparia  X  Rupes- 
tris 3306  will  more  than  hold  its  own. 


*J.  Dufour  in  "Chronique  Agricole  du  Canton  de  Vaud,"  quoted  by  G.  Foex, 
"  Cours  Complet  de  Viticulture,"  4th  ed.,  page  603. 

t  J.  Bonjour:  "  Manuel  Pratique  du  Vigneron,"  page  71. 

\  J.  Jallabert:  "  Resistance  du  Rupestris  du  Lotet  du  Riparia  X  Rupestris  3306  au 
Pourridie,"  Revue  de  Viticulture,  tome  XI,  page  92. 

§  Loc.  cit.,  page  5)4  et  suiv. 


CALIFORNIA  PUBLICATIONS  AVAILABLE  FOR  DISTRIBUTION. 


REPORTS. 

1896.  Report   of   the    Viticultural    Work   during   the   seasons    1887-93,    with   data 

regarding  the  Vintages  of  1894-95. 

1897.  Resistant   Vines,   their   Selection,   Adaptation,   and   Grafting.     Appendix   to 

Viticultural  Report  for  1896. 

1898.  Partial  Report  of  Work  of  Agricultural  Experiment  Station  for  the  years 

1895-96  and  1896-97. 
1900.     Report  of  the  Agricultural  Experiment  Station  for  the  year  1897-98. 

1902.  Report  of  the  Agricultural  Experiment  Station  for  1898-1901. 

1903.  Report  of  the  Agricultural  Experiment  Station  for  1901-1903. 

1904.  Twenty-second  Report  of  the  Agricultural  Experiment  Station  for  1903-1904. 

BULLETINS. 

Reprint.     Endurance  of  Drought  in  Soils  of  the  Arid  Region. 
No.  129.     Report  of  the  Condition  of  Olive  Culture  in  California. 
•131.     The  Phylloxera  of  the  Vine. 

132.  Feeding  of  Farm  Animals. 

133.  Tolerance  of  Alkali   by   Various   Cultures. 
135.     The  Potato- Worm  in  California. 

137.  Pickling  Ripe  and  Green  Olives. 

138.  Citrus  Fruit  Culture. 

139.  Orange  and  Lemon  Rot. 

140.  Lands  of  the  Colorado  Delta  in  Salton  Basin,  and  Supplement. 

141.  Deciduous  Fruits  at  Paso  Robles. 

142.  Grasshoppers  in  California. 

143.  California   Peach-Tree    Borer. 

144.  The  Peach-Worm. 

145.  The  Red  Spider  of  Citrus  Trees. 

146.  New  Methods  of  Grafting  and   Budding   Vines. 

147.  Culture  Work  of  the  Substations. 

148.  Resistant  Vines  and  their  Hybrids. 

149.  California   Sugar   Industry. 

150.  The  Value  of  Oak  Leaves  for  Forage. 

151.  Arsenical  Insecticides. 

152.  Fumigation  Dosage. 

153.  Spraying  with  Distillates. 

154.  Sulfur  Sprays  for  Red  Spider. 

155.  Directions  for  Spraying  for  the  Codling-Moth. 

156.  Fowl   Cholera. 

157.  Commercial   Fertilizers. 

158.  California  Olive  Oil;  its  Manufacture. 

159.  Contribution  to  the  Study  of  Fermentation. 

160.  The  Hop  Aphis. 

161.  Tuberculosis   in   Fowls. 

162.  Commercial  Fertilizers. 

163.  Pear  Scab. 

164.  Poultry  Feeding  and  Proprietary  Foods. 

165.  Asparagus  and  Asparagus  Rust  in  California. 

166.  Spraying  for  Scale  Insects. 

167.  Manufacture  of  Dry  Wines  in  Hot  Countries. 

CIRCULARS. 

No.  1.     Texas   Fever.  No.  10.     Reading    Course     in     Economic 

2.  Blackleg.  Entomology. 

3.  Hog  Cholera.  11.     Fumigation   Practice. 

4.  Anthrax.  12.     Silk   Culture. 

5.  Contagious  Abortion  in  Cows.  13.     The  Culture  of  the  Sugar  Beet. 

6.  Methods  of  Physical  and  Chem-  14.     Practical    Suggestions   for   Cod- 

ical   Soil  Analysis.  ling-Moth      Control      in      the 

7.  Remedies  for  Insects.  Pajaro  Valley. 
9.     Asparagus  Rust. 

Copies  may  be  had  by  application  to  the  Director  of  the  Experiment 
Station,  Berkeley,  California. 


UNIVERSITY  OF  CALIFORNIA  AGRICULTURAL  EXPERIMENT  STATION 

COLLEGE  OF  AGRICULTURE  E.  j.  WICKSON,  ACTING  DIRECTOR 

BERKELEY,   CALIFORNIA 


CIRCULAR  No.  26 

(SEPTEMBER,  1906.) 


SELECTION  AND  PREPARATION  OF  VINE-CUTTINGS, 


BY 

FEEDEEIC  T.  BIOLETTI. 


One  of  the  most  important  factors  in  determining  the  profitableness 
of  a  vineyard  is  the  choice  of  the  cuttings  which  are  used  to  start  the 
vineyard.  This  factor  is  very  generally  neglected,  or  when  a  choice  is 
made  it  is  often  not  the  best. 

Any  one  who  will  carefully  examine  the  vines  in  a  vineyard  cannot 
help  being  struck  with  the  great  variation  in  the  amount  of  crop  on 
different  individual  vines.  Sometimes  this  variation  can  be  traced  to 
differences  in  pruning,  to  accidental  injuries,  to  more  or  less  irrigation, 
or  to  variations  in  soil  and  position.  There  is,  however,  a  good  deal  of 
variation  which  cannot  be  ascribed  to  any  of  these  causes  and  which 
exists  in  every  vineyard,  no  matter  how  uniform  the  conditions  or  how 
careful  the  cultivation. 

This  variation  is  something  which  is  inherent  in  the  vine  and  can- 
not be  overcome  by  any  cultural  method.  It  is  much  greater  in  some 
varieties  than  in  others.  With  some  varieties  it  is  so  great  that  certain 
vines  are  recognized  as  almost  sterile  and  are  commonly  called  "mule" 
vines  in  California.  With  other  varieties  the  variation  is  much  less 
noticeable,  but  is  none  the  less  real,  and  by  weighing  the  crop  of  each 
vine  in  a  row  it  will  be  found,  even  with  the  most  uniform  producers, 
to  exceed  50  per  cent.  If  every  vine  in  the  vineyard  bore  as  much  as 
the  vine  with  the  heaviest  crop  the  total  production  of  the  vineyard 
would  be  much  increased.  By  grafting  the  poor  bearers  with  cuttings 
from  the  best  bearers  the  crop  in  a  vineyard'  has  been  more  than  dou- 
bled. Vineyards  of  unselected  Cabernet  produce  on  the  average  about 
two  tons  to  the  acre.  Cabernet  vineyards  from  carefully  selected  cut- 
tings have  produced  nine  tons. 

Owing  to  the  great  natural  fertility  of  most  of  our  Calif ornian 
vineyards,  due  to  favorable  soil  and  climate,  these  facts  have  not  re- 
ceived the  attention  they  deserve.  In  most  parts  of  Europe,  and  even 
in  South  Africa,  more  care  is  taken  in  the  selection  of  cuttings  than 
here.  In  many  vineyards  the  vines  bearing  the  best  crops  are  marked 
and  cuttings  taken  only  from  these.  In  others  only  those  cuttings  are 
used  which  are  made  from  bearing  wood ;  that  is,  from  canes  which 
have  borne  grapes,  as  shown  by  the  remains  of  the  bunch  stalks,  or  by 
the  position  of  the  cane  on  the  vine. 


UNIVERSITY  OF  CALIFORNIA  AGRICULTURAL  EXPERIMENT  STATION 

-COLLEGE  OF  AGRICULTURE  E.  j.  WICKSON,  ACTING  DIRECTOR 

BERKELEY,   CALIFORNIA 


CIRCULAR  No.  26 

(SEPTEMBER,  1906.) 


SELECTION  AND  PREPARATION  OF  VINE-CUTTINGS. 


BY 

FEEDEEIC  T.  BIOLETTI. 


One  of  the  most  important  factors  in  determining  the  profitableness 
of  a  vineyard  is  the  choice  of  the  cuttings  which  are  used  to  start  the 
vineyard.  This  factor  is  very  generally  neglected,  or  when  a  choice  is 
made  it  is  often  not  the  best. 

Any  one  who  will  carefully  examine  the  vines  in  a  vineyard  cannot 
help  being  struck  with  the  great  variation  in  the  amount  of  crop  on 
different  individual  vines.  Sometimes  this  variation  can  be  traced  to 
differences  in  pruning,  to  accidental  injuries,  to  more  or  less  irrigation, 
or  to  variations  in  soil  and  position.  There  is,  however,  a  good  deal  of 
variation  which  cannot  be  ascribed  to  any  of  these  causes  and  which 
exists  in  every  vineyard,  no  matter  how  uniform  the  conditions  or  how 
careful  the  cultivation. 

This  variation  is  something  which  is  inherent  in  the  vine  and  can- 
not be  overcome  by  any  cultural  method.  It  is  much  greater  in  some 
varieties  than  in  others.  With  some  varieties  it  is  so  great  that  certain 
vines  are  recognized  as  almost  sterile  and  are  commonly  called  ' '  mule ' ' 
vines  in  California.  With  other  varieties  the  variation  is  much  less 
noticeable,  but  is  none  the  less  real,  and  by  weighing  the  crop  of  each 
vine  in  a  row  it  will  be  found,  even  with  the  most  uniform  producers, 
to  exceed  50  per  cent.  If  every  vine  in  the  vineyard  bore  as  much  as 
the  vine  with  the  heaviest  crop  the  total  production  of  the  vineyard 
would  be  much  increased.  By  grafting  the  poor  bearers  with  cuttings 
from  the  best  bearers  the  crop  in  a  vineyard'  has  been  more  than  dou- 
bled. Vineyards  of  unselected  Cabernet  produce  on  the  average  about 
two  tons  to  the  acre.  Cabernet  vineyards  from  carefully  selected  cut- 
tings have  produced  nine  tons. 

Owing  to  the  great  natural  fertility  of  most  of  our  Californian 
vineyards,  due  to  favorable  soil  and  climate,  these  facts  have  not  re- 
ceived the  attention  they  deserve.  In  most  parts  of  Europe,  and  even 
in  South  Africa,  more  care  is  taken  in  the  selection  of  cuttings  than 
here.  lii  many  vineyards  the  vines  bearing  the  best  crops  are  marked 
and  cuttings  taken  only  from  these.  In  others  only  those  cuttings  are 
used  which  are  made  from  bearing  wood;  that  is,  from  canes  which 
have  borne  grapes,  as  shown  by  the  remains  of  the  bunch  stalks,  or  by 
the  position  of  the  cane  on  the  vine. 


It  is  perhaps  not  right  to  say  that  no  choice  is  exercised  in  the  selec- 
tion of  cuttings  in  California.  There  is  inevitably  some  choice,  though 
principally  unconscious  and  generally  harmful.  The  man  who  is  mak- 
ing cuttings  will,  if  he  has  no  other  standard,  choose  those  canes  which 
he  can  work  up  with  the  greatest  ease.  These  are  the  long,  unbranched 
canes  from  the  most  vigorous  vines.  Such  canes  are  usually  suckers  or 
water-sprouts,  the  least  fruitful  on  the  vine,  and  the  most  vigorous 
vines  are  generally  those  which  have  produced  the  fewest  grapes.  Such 
selection  as.  this  cannot  fail  to  be  harmful,  especially  with  the  finer  va- 
rieties, which  vary  more  than  the  common,  and  must  finally  result  in 
the  deterioration  of  all  varieties. 

The  ordinary  European  method  of  simply  marking  the  vines  which 
bear  good  crops  the  year  the  cuttings  are  taken  is  imperfect  and  can 
do  no  more  than  keep  the  varieties  from  deteriorating.  By  more  care- 
ful selection,  continued  systematically  for  a  series  of  years,  it  has  been 
proved  possible  to  greatly  increase  the  bearing  qualities  of  certain  va- 
rieties. Other  qualities  besides  that  of  more  or  less  productiveness 
could  undoubtedly  be  influenced  by  the  same  means.  In  this  way  nu- 
merous variations  of  the  Pinot  or  Burgundy  have  arisen.  These  varia- 
tions differ  from  the  type  in  color,  acidity,  time  of  ripening,  and  even 
in  flavor.  It  would  probably  be  possible  to  produce  a  loose  bunched 
Tokay,  a  close  bunched  Zabalkanski,  or  a  large  fruited  Sultanina  in  the 
same  way. 

There  is  no  quality,  however,  which  varies  so  much  with  individual 
vines  as  that  of  bearing,  and  there  is  no  quality  that  is  so  quickly  and 
easily  influenced  by  cutting  selection.  It  is  this  quality,  therefore, 
which  should  receive  most  attention  in  choosing  our  cuttings.  The 
modification  of  other  characteristics  is  the  work  of  the  plant  breeder 
and  is  too  slow,  difficult  and  uncertain  for  the  practical  grape  grower. 
It  is,  moreover,  at  least  in  the  case  of  wine  grapes,  unnecessary,  for  we 
can  find  almost  any  quality  we  want  among  the  two  or  three  thousand 
known  varieties  of  wine  grapes,  but  unfortunately  not  always  com- 
bined with  high  productiveness.  The  most  promising  means  of  obtain- 
ing the  rara  avis  we  desire  is  to  commence  with  a  variety  possessing 
the  necessary  flavor,  color  and  chemical  composition  and  by  proper  cut- 
ting selection  to  bring  up  its  productiveness  to  the  desired  degree.  It 
would  be  much  easier  to  "grade  up"  the  Cabernet  until  it  bore  crops 
equal  to  those  of  the  Carignane  than  to  attempt  to  improve  greatly  the 
flavor  and  color  of  Carignane  by  selection. 

Method  of  Selection,  The  first  question  to  be  settled  is,  of  course, 
what  variety  should  be  chosen.  This  will  depend  on  whether  it  is  in- 
tended to  raise  table,  raisin,  or  wine  grapes,  and  if  wine  grapes,  on  the 
kind  of  wine  desired,  sweet  or  dry,  red  or  white,  and  also  on  a  multi- 
plicity of  local  and  market  conditions.  The  question  of  variety  is  too 
lar^e  and  complicated  for  treatment  here  and  has  already  been  given 
much  attention  in  various  publications  of  the  Station.  Only  the  ques- 
tions regarding  the  means  of  obtaining  cuttings  capable  of  growing 
into  strong,'  heavy  bearing  vines  will  be  considered  here. 


The  Locality.  Any  locality  where  the  vine  grows  vigorously  and 
ripens  its  wood  regularly  will  produce  good  cuttings.  As  a  rule  the 
warmer  localities  produce  the  best  wood,  heavy,  firm  and  well  nour- 
ished. The  canes  on  vines  grown  very  near  the  coast,  as  at  Berkeley, 
are  often  soft  and  pithy.  Certain  varieties  such  as  Refosco  and 
Almeria  do  not  ripen  their  wood  well  in  the  cooler  parts  even  of 
Sonoma  and  Santa  Cruz  counties  where  they  are  exposed  to  frequent 
sea  fogs  during  the  summer.  Being  immature  when  the  frosts  cause 
the  leaves  to  fall,  the  canes  are  easily  attacked  by  saprophytic  fungi. 
The  work  of  these  fungi  is  often  seen  in  the  blackened  or  mottled  ap- 
pearance of  the  canes.  Any  discoloration  of  the  canes  is  a  bad  sign, 
whether  it  is  caused  by  fungi  wl^ich  only  attack  imperfectly  matured 
wood,  or  by  parasitic  fungi,  such  as  oidium,  which  may  occur  any- 
where. With  the  exception  of  a  few  isolated  localities  quite  near  the 
coast,  it  may  be  said  that  good,  well  ripened  cuttings  may  be  obtained 
from  any  of  the  vine-growing  regions  of  California. 

Vine  Diseases.  An  exception  should  perhaps  be  made  to  this  state- 
ment as  regards  localities  where  the  so-called  Anaheim  disease  is  prev- 
alent. Until  we  know  more  about  that  disease  it  is  wiser  to  avoid 
obtaining  our  cuttings  from  such  regions.  That  this  disease  can  be 
transported  and  communicated  by  cuttings  is  perhaps  not  thoroughly 
demonstrated,  but  at  all  events  the  disease  results  in  poor  growth  and 
poor  wood,  and  cuttings  from  diseased  vines  cannot  be  expected  to  give 
the  best  results. 

With  regard  to  other  diseases  there  need  be  no  fear  of  their  intro- 
duction into  the  vineyard  by  means  of  cuttings.  Phylloxera  can  be 
guarded  against  by  proper  disinfection  of  the  cuttings  and  all  other 
vine  diseases,  which  exist  in  California,  are  found  in  every  district. 
This  is  not  true  as  regards  rooted  cuttings.  There  is  no  sure  and  prac- 
ticable method  of  destroying  Phylloxera  on  the  roots,  and  rooted  vines 
should  be  introduced  into  a  new  district  only  with  extreme  caution. 

While  there  need  be  no  fear  of  introducing  Oidium,  vine-hoppers, 
etc.,  for  they  exist  in  every  vine-growing  region  of  California,  no  cut- 
tings should  be  used  which  show  distinct  signs  of  their  attacks,  as  such 
signs  are  proof  that  the  vines  from  which  the  cuttings  came  were  not 
perfectly  healthy,  and  unhealthy  vines  do  not  produce  the  best  cut- 
tings. 

The  Vineyard.  As  a  rule  it  is  best  to  obtain  the  cuttings  in  the 
district  where  they  are  to  be  planted,  if  the  desired  variety  is  grown 
there.  The  only  exceptions  to  this  rule  are  for  districts  where  Ana- 
heim, Oidium,  or  some  other  disease  is  so  prevalent  that  it  is  difficult 
to  find  perfectly  healthy  vines. 

The  locality  being  decided  on,  it  is  not  a  matter  of  indifference 
what  vineyard  is  chosen.  Only  a  well  kept,  vigorous  vineyard  can  pro- 
duce the  best  cuttings.  If  the  vineyard  is  badly  cultivated,  the  vines 
mildewed,  or  the  grapes  of  poor  quality,  it  is  a  bad  source  for  our  cut- 
tings. A  vineyard  which  has  healthy  vines  producing  paying  crops  of 
good  grapes  is  the  best  place  to  get  them. 


The  Vines.  Given  the  locality  and  the  vineyard :  from  which  vines 
in  this  vineyard  shall  we  take  our  cuttings  ?  This  is  the  most  impor- 
tant question  of  all  and  that  which  is  most  generally  neglected.  It  is 
hardly  necessary  to  say  that  no  cuttings  should  be  taken  from  vines 
which  have  never  produced  a  good  crop.  Some  such  vines  exist  in 
nearly  every  vineyard.  A  few  growers  mark  such  vines  and  avoid 
them  when  making  cuttings.  It  would  be  better  to  graft  them  over  or 
dig  them  out. 

Instead  of  marking  the  poorest  vines  in  order  to  avoid  them,  it  is 
better  to  mark  the  best  vines  in  order  to  choose  them  when  making  cut- 
tings. When  the  crop  is  ripe  and  still  on  the  vines  the  vineyard  should 
be  gone  over  carefully  and  a  sufficient  number  of  the  best  vines  marked 
to  supply  the  amount  of  cuttings  needed.  Only  vines  showing  health, 
vigor  and  heavy  crop  of  well-ripened  grapes  should  be  marked.  A  dab 
of  paint  on  the  stake  or  the  stem  of  the  vine  is  perhaps  the  most  con- 
venient way  of  marking. 

While  this  will  insure  our  cuttings  coming  only  from  vines  which 
are  capable  of  producing  a  satisfactory  crop,  it  omits  one  very  impor- 
tant factor — the  regularity  of  bearing.  Some  vines  bear  good  crop 
occasionally,  or  on  alternate  years.  The  ideal  vine  is  one  which  bears 
a  good  crop  every  year.  This  vine  we  can  find  only  by  keeping  a  con- 
tinuous record  of  its  performance.  This  can  be  done  to  some  extent 
by  going  over  the  vineyard  every  year  just  before  the  vintage  and 
marking  every  vine  which  has  a  good  crop.  At  the  end  of  four  or  five 
years  the  vines  which  have  borne  a  good  crop  every  year  will  show  four 
or  five  marks,  and  these  are  the  vines  most  likely  to  yield  cuttings  ca- 
pable of  producing  a  vineyard  of  ideal  vines. 

To  make  this  selection  most  effectively  and  quickly  would  require 
a  special  vineyard  for  the  purpose.  A  vineyard  of  pedigreed  vines  of 
all  our  most  desirable  varieties  would  be  a  most  valuable  acquisition 
for  the  State.  Such  a  vineyard  might  be  started  with  cuttings  selected 
in  the  way  described,  and  each  variety  gradually  brought  up  to  its 
highest  possible  bearing  capacity,  by  grafting  all  the  vines  of  each 
variety  with  cuttings  taken  from  the  vine  of  that  variety  which  had 
shown  the  best  and  most  regular  bearing  qualities  during  a  term  of 
years.  Twenty-five  or  thirty  such  vines  of  each  variety  would  be  suffi- 
cient to  maintain  and  improve  the  productiveness  of  all  the  vineyards 
in  the  State  if  it  were  used  to  supply  stock  to  nurserymen  and  other 
growers  of  vine  cuttings.  This  would  make  it  unnecessary  to  abandon 
many  of  the  finest  varieties  of  grapes,  as  has  been  done  to  a  great  ex- 
tent lately. 

Part  of  the  Vine.  While  any  cutting  from  a  good  vine  is  probably 
better  than  the  best  cutting  from  a  poor  vine,  it  is  not  a  matter  of  in- 
difference from  what  part  of  the  vine  the  cuttings  are  taken.  It. is  a 
well  established  fact  known  to  all  skilled  pruners  that  certain  buds  on 
a  vine  are  much  more  likely  to  produce  fruit  than  others.  These  buds 
may  be  called,  from  analogy  with  similar  bud  on  orchard  trees,  fruit 
buds.  The  fruit  buds  of  vines,  unlike  those  of  most  orchard  trees,  are 


not  distinguishable  by  shape  or  size  from  wood  or  sterile  buds.  They 
can  be  recognized  only  by  their  position. 

The  buds  on  suckers  (canes  from  below  the  ground)  or  water- 
sprouts  (canes  from  the  trunk  or  older  parts  of  the  arms)  are  usually 
unfruitful  with  most  varieties.  The  only  buds  which  can  be  depended 
on  to  give  fruit  are  those  on  canes  which  have  grown  on  wood  of  the 
previous  year,  or  as  pruners  usually  express  it,  * '  fruit  spurs  and  fruit 
canes  consist  of  one-year-old  wood  growing  out  of  two-year-old  wood. ' ' 
The  canes  of  such  wood  are  called  by  the  grape-growers  of  South  Af- 
rica "bearers,"  and  no  others  are  used  for  making  cuttings. 

Now,  while  the  choice  of  this  wood  is  perfectly  safe,  it  has  not  been 
demonstrated  that  such  choice  is  necessary.  It  may  be  that  cuttings 
taken  from  heavy  bearing  vines  will  grow  into  other  heavy  bearing 
vines  whether  they  have  originally  been  water-sprouts  or  fruit  wood. 
This  seems  probable,  for  in  pruning  vines  it  is  constantly  necessary  to 
use  water-sprouts  to  form  spurs  for  the  purpose  of  replacing  lost  arms 
or  for  shortening  arms  which  have  grown  too  long.  Now,  while  these 
spurs  bear  little  or  no  fruit  the  first  year,  they  give  rise  to  wood  the 
following  year,  which  satisfies  the  primer's  definition  of  fruit  wood, 
viz.,  "one-year-old  wood  out  of  two-year-old  wood,"  and  which  is  ap- 
parently as  fruitful  as  any  wood  on  the  vine.  A  sucker,  or  water- 
sprout  from  a  fruitful  vine,  therefore,  is  to  be  preferred  in  making 
cuttings  to  a  fruit  cane  from  a  vine  which  bears  small  crops. 

All  canes  and  all  parts  of  the  cane,  however,  are  not  equally  suit- 
able for  cuttings.  Very  small,  thin  canes  are  apt  to  be  ill-nourished 
and  immature,  as  are  also  the  tips  of  better  canes.  Many  cuttings 
made  from  such  material  are  apt  to  fail,  or  give  weak  vines.  Very 
large,  over-grown  cuttings  are  also  to  be  avoided.  Many  growers  avoid 
using  the  two  or  three  buds  nearest  the  base  of  the  cane  on  the  ground 
that  such  buds  are  not  fruit  buds,  but  the  same  reasoning  may  be  ap- 
plied to  this  case  as  to  that  of  water-sprouts.  A  medium  sized  cutting 
between  three-eighths  and  five-eighths  inches  in  diameter  is  most  likely 
to  give  good  results. 

Form  and  Length  of  Cutting.  It  was  formerly  considered  good 
practice  to  leave  a  piece  of  old  wood  attached  to  the  base  of  the  cut- 
ting, on  the  ground  that  such  cuttings  always  grew.  This  practice  is 
now  very  generally  abandoned,  as  it  often  gives  rise  to  weak  and  dis- 
eased vines.  The  piece  of  old  wood  always  decays  finally,  and  the 
decay  may  spread  into  the  trunk  and  roots  of  the  vine.  A  good  cut- 
ting should  consist  exclusively  of  one-year-old  wood ;  that  is,  the  wood 
which  has  grown  during  the  current  season. 

The  form  and  length  of  the  cuttings  will  depend  on  the  use  that  is 
to  be  made  of  them.  If  they  are  to  be  used  as  scions  for  grafting  they 
may  be  cut  up  in  any  way  and  of  any  length  that  is  found  convenient 
for  handling  and  keeping  them  in  good  condition.  If  they  are  to  be 
used  for  rooting  either  in  the  nursery  or  the  vineyard  it  is  most  con- 
venient to  cut  them  up  into  the  exact  lengths  which  are  to  be  planted. 

The  length  will  depend  altogether  on  the  soil  and  climate  where 


they  are  to  be  planted.  They  should  be  of  such  a  length  that  when 
planted  the  base  of  the  cutting  will  be  at  the  level  where  the  conditions 
are  most  favorable  to  root  formation.  If  the  base  is  too  deep,  it  will  be 
too  wet  and  too  cold  to  develop  roots.  Roots  will  start  higher  up  and 
the  bottom  part  will  be  wasted,  or  worse  still,  may  decay  and  injure 
the  vine.  If  the  base  is  too  near  the  surface  the  whole  cutting  may  dry 
out  and  die  before  its  roots  have  developed  sufficiently  to  supply  it 
with  water. 

In  the  moister  soils  of  the  cooler  districts  a  cutting  10  inches  long 
is  sufficient  for  direct  planting  in  the  vineyard.  In  the  drier  and 
warmer  interior  a  14-  to  16-inch  cutting  is  better,  while  in  the  driest 
soils  of  the  warmest  districts  it  is  often  necessary  to  have  a  cutting  18 
to  20  inches  long.  For  planting  in  the  nursery  a  12-  or  14-inch  cutting 
is  about  the  most  convenient.  If  the  soil  of  the  nursery  is  wet  and  cold 
more  of  the  cutting  should  be  left  above  ground;  if,  on  the  contrary, 
the  soil  tends  to  be  hot  and  dry  the  cutting  must  be  planted  deeper 
and  even  covered  up  completely. 

It  is  not  necessary,  or  possible,  to  make  every  cutting  of  exactly  the 
same  length,  because  they  should  all  terminate  at  each  end  at  a  node. 
A  vine  cane  consists  of  nodes  where  the  buds  are  and  internodes  be- 
tween the  buds.  The  pith  is  interrupted  at  each  node  by  a  woody  par- 
tition which  extends  through  the  cane  at  each  bud.  In  making  a  cut- 
ting, therefore,  we  should  cut  exactly  through  a  bud  both  at  the  top 
and  at  the  bottom.  This  will  leave  the  woody  partitions,  which  will 
prevent  decay  at  the  bottom  and  drying  out  at  the  top. 

Conservation  of  Cuttings.  In  some  cases  vine  cuttings  may  be 
planted  with  success  as  soon  as  they  are  made.  This  can  be  done  only 
in  light,  well-drained  soils  where  there  is  no  danger  of  the  ground  be- 
coming water-logged  and  remaining  in  this  condition  for  some  time. 
Except  in  such  cases  it  is  better  to  defer  the  planting  of  the  cuttings 
until  most  of  the  winter  rains  are  over  and  the  soil  commences  to  warm 
up  in  the  Spring. 

To  preserve  the  cuttings  in  good  condition  until  this  time  they  must 
be  kept  from  drying  out  or  being  injured  by  too  much  moisture.  If 
they  are  buried  in  sand  or  loose  soil  in  such  a  way  that  at  least  the 
butts  are  in  contact  with  the  soil  they  will  keep  well  until  April.  The 
sand  should  be  comparatively  dry  and  well  sifted  in  to  the  centers  of 
the  bundles  of  cuttings.  These  bundles  should  be  small  and  if  they 
are  to  remain  in  the  sand  for  more  than  two  weeks  they  should  be 
loosely  tied,  or  better  still,  not  tied  at  all,  but  simply  buried  in  thin 
layers.  Unless  the  sand  is  in  contact  with  the  cuttings  nearly  every- 
where, many  will  dry  out  and  die  if  the  sand  is  dry,  or  they  will  mold 
and  decay  if  the  sand  is  moist. 

A  good  place  to  bury  the  cuttings  is  a  shed  or  cellar  or  on  the  north 
side  of  a  building.  If  such  a  place  is  unobtainable  they  may  be  put  in 
a  hole  at  least  as  deep  as  the  cuttings  and  covered  up  well  with  soil. 
Over  this  soil  should  be  placed  a  thick  bed  of  straw,  or  other  material, 
to  prevent  the  soil  drying  or  becoming  too  warm.  This  last  precaution 


is  particularly  necessary  if  the  planting  is  to  be  delayed  until  late 
Spring,  for  otherwise  the  buds  and  roots  may  start.  Cuttings  which 
have  started  slightly  before  being  planted  will  often  grow,  but  they  do 
not  make  the  best  growth. 

Above  all,  the  cuttings  must  be  protected  from  too  much  moisture. 
A  cutting  injured  by  being  kept  too  wet  is  useless,  while  one  kept  a 
little  too  dry  will  give  good  plants  if  soaked  in  water  for  a  day  or  two 
before  being  planted. 

Definition  of  Good  Vine  Cuttings. 

They  should  be : — 

1.  Taken  from  a  healthy  vine  which  has  borne  good  crops  regularly. 

2.  Of  medium  size,  one-third  to  two-thirds  inch  in  diameter. 

3.  Made  from  bearing  wood  (?). 

4.  Well  ripened,  as  shown  by  firmness  of  wood,  light  colored  pith  and  well- 

formed  buds. 

5.  Healthy,  as  shown  by  clear,  uniform  color. 

6.  Medium  jointed  (length  of  joints  varying  according  to  variety). 

7.  Moist.    It  should  be  possible  to  squeeze  out  a  little  sap  from  a  newly  made 

cut. 

8.  Uninjured  by  too  much  moisture.     The  pith  should  not  have  turned  black 

or  the  bark  have  become  loose. 

9.  Of  the  length  most  suited  to  the  place  where  they  are  to  be  planted. 
10.     Cut  through  a  bud  both  at  top  and  bottom. 


PUBLICATIONS. 


COLLEGE  OF  AGRICULTURE, 

AGRICULTURAL  EXPERIMENT  STATION 


RESISTANT    VINEYARDS 


GRAFTING, 


PLANTING,  CULTIVATION, 


BY  FREDERIC  T.  BIOLETTI. 


Vineyard  of  Bench-grafts.    One  failed  out  of  750  planted. 


BULLETIN    No.    180. 


W.  W.  SHANNON, 


SACRAMENTO: 

SUPERINTENDENT  STATE  PRINTING 
1906. 


BENJAMIN   IDE  WHEELER,  Ph.D.,LL.D.,  President  of  the  University, 


EXPERIMENT  STATION  STAFF. 

E.  J.  WICKSON,  M.A.,  Acting  Director  and  Horticulturist. 

E.  W.  HILGARD,  Ph.D.,  LL.D.,  Chemist. 

W.  A.  SETCHELL,  Ph.D.,  Botanist. 

ELWOOD  MEAD,  M.S.,  C.E.,  Irrigation  Engineer. 

C.  W.  WOODWORTH,  M.S.,  Entomologist. 

R.  H.  LOUGHRIDGE,  Ph.D.,  Agricultural  Geologist  and  Soil  Physicist.     (Soils  and  Alkali .)    (Ab- 

M.  E.  JAFFA,  M.S.,  Chemist.     (Foods,  Nutrition.)  [sent  on  leave.) 

G.  W.  SHAW,  M.A.,  Ph.D.,  Chemist.    (Cereals,  Oils,  Beet-Sugar.) 

GEORGE  E.  COLBY,  M.S.,  Chemist.    (Fruits,  Waters,  Insecticides) 

RALPH  E.  SMITH,  B.S.,  Plant  Pathologist. 

A.  R.  WARD,  B.S.A.,  D.V.M.,  Veterinarian  and  Bacteriologist. 

E.  W.  MAJOR,  B.Agr.,  Animal  Industry. 

F.  T.  BIOLETTI,  M.S.,  Viticulturist.     (Grapes,  Wine,  and  Zymology.) 
H.  M.  HALL,  M.S.,  Assistant  Botanist. 

JOHN  S.  BURD,  B.S.,  Chemist,  in  charge  of  Fertilizer  Control. 

C.  M.  HARING,  D.V.M.,  Assistant  Veterinarian  and  Bacteriologist. 
ALBERT  M.  WEST,  B.S.,  Assistant  Plant  Pathologist. 

E.  H.  SMITH,  M.S.,  Assistant  Plant  Pathologist. 

G.  R.  STEWART,  Student  Assistant  in  Station  Laboratory. 
,  Assistant  in  Soil  Laboratory. 

RALPH  BENTON,  B.S.,  Assistant  in  Entomology. 

LUDWIG  ROSENSTEIN,  Laboratory  Assistant  in  Fertilizer  Control. 

ALFRED  TOURNIER,  Assistant  in   Viticulture. 

HANS  HOLM,  Student  Assistant  in  Zymology. 

A.  J.  GAUMITZ,  Assistant  in  Cereal  Laboratory. 

J.  C.  BRADLEY,  A.B.,  Assistant  in  Entomology. 

D.  L.  BUNNELL,  Clerk  to  the  Director. 


R.  E.  MANSELL,  Foreman  of  Central  Station  Grounds. 

JOHN  TUOHY,  Patron,      )      , 

>     Tulare  Substation,  Tulare. 
,  Foreman,        ) 

J.  W.  MILLS,  Pomona,  in  charge  Cooperative  Experiments  in  Southern  California. 

J.  W.  ROPER,  Patron,  ) 

>  University  Forestry  Station,  Chico. 
E.  C.  MILLER  In  charge,         ) 

>  University  Forestry  Station,  Santa  Monica. 
N.  D.  INGHAM,  Foreman,      ) 

VINCENT  J.  HUNTLEY,  Foreman  of  California  Poultry  Experiment  Station,  Petaluma. 


The  Station  publications  (REPORTS  AND  BULLETINS),  so  long  as  avail- 
able, will  be  sent  to  any  citizen  of  the  State  on  application. 


CONTENTS. 


PAGB. 

INTRODUCTION -—  89 

I.  THE  NURSERY— 

Choice  and  preparation  of  the  soil. 93 

Grafting  cuttings. . - 94 

Choice  of  cuttings -.. 94 

Mother  vines . --.  95 

Making  and  conservation  of  cuttings 98 

Time  of  grafting _ 100 

Preparation  of  stocks 100 

Preparation  of  scions 102 

Grading  cuttings . 102 

Methods  of  uniting  stock  and  scion 106 

Tongue  grafting 108 

Wire  grafting 110 

Making  bundles 111 

Grafting  rooted  cuttings .: 112 

Callusing 113 

Planting  in  the  nursery 118 

Cultivation  in  the  nursery 121 

Removal  of  scion  roots ...- _ 124 

Removal  of  raffia  and  suckers ..-  124 

Digging  the  grafts 125 

Sorting  the  grafts ...  125 

Pruning  the  grafts --. 126 

Conservation  and  shipping 128 

Nursery  grafting 128 

II.  THE  VINEYARD- 

Preparation  of  the  soil 129 

Fertilization 129 

Intercalary  crops 130 

Planting _ _ .- 130 

Pruning 133 

Staking 133 

Suckering  and  rooting '. _ 134 

Cultivation..  134 


Ixxxviii  CONTEXTS. 

HI.     FIELD  GRAFTING—  PAGE. 

Preparation  of  the  soil ..  135 

Cuttings  or  roots - 135 

Age  for  grafting . 136 

Methods  of  grafting 136 

Tying  and  waxing 138 

Season  for  field  grafting 138 

Treatment  the  first  year.. .  ..  138 

Regrafting 139 

Herbaceous  grafting 140 

Comparison  of  various  methods 142 

ILLUSTRATIONS. 

Young  vineyard  of  bench-grafts .- ^  (cover) 

FIG.    1.    Effect  of  scion  roots  on  old  vines . 92 

2.  Mother  vines  of  resistant  stock. . 99 

3.  Gauge  for  cutting  stocks 101 

4.  Notch  and  slot  graders 103 

5.  Slot  grader  setup 103 

6.  Scales  for  slot  grader 105 

7.  Various  methods  of  bench  grafting 107 

8.  Method  of  holding  knife .. 108 

9.  Wire-cutter 110 

10.  Bundle  stand 111 

11.  Callusing  bed . 113 

12.  Plan  of  callusing  bed 114 

13.  Callused  wire  graft : 114 

14.  Effects  of  moisture  on  callus  formation 115 

15.  Root  and  callus  formation 116 

16.  Effect  of  temperature  on  callus  formation 117 

17.  Callused  whip  grafts 118 

18.  Planting  dibbles 120 

19.  Method  of  planting  in  nursery  with  dibble... 121 

20.  Method  of  planting  in  nursery  in  trenches 121 

21.  Irrigating  a  nursery. 122 

22.  Scion  roots  on  bench  grafts. 123 

23.  Grafts  strangled  by  raffia. 125 

24.  No.  1  bench  grafts 127 

25.  Method  of  planting  grafts  in  vineyard. 131 

26.  Methods  of  field  grafting 137 

27.  Scion  roots  in  field-grafted  vine.. 139 

28.  Herbaceous  graft 140 

29.  Herbaceous  bud ....     ...'...  141 


RESISTANT  VINEYARDS. 

GRAFTING,   PLANTING,  AND    CULTIVATION. 

BY  FREDERIC  T.   BIOLETTI. 

INTRODUCTION. 

There  is  no  subject  connected  with  grape-growing  about  which  there 
is  more  general  demand  for  information  in  California  than  that  of  the 
growing  of  resistant  vines.  Innumerable  inquiries  are  received  at 
the  Experiment  Station  regarding  methods  of  planting,  grafting,  and 
cultivating  phylloxera-resistant  vineyards.  Several  bulletins  on  various 
phases  of  this  subject  have  been  published  by  the  Station,  but  they 
are  all  somewhat  out  of  date  at  this  time,  and  the  editions  of  most  of 
them  are  exhausted. 

The  two  phases  of  the  subject  about  which  there  seems  to  be  most 
pressing  need  for  information  are  the  determination  of  the  best  varieties 
of  resistant  stocks  for  the  various  soils  and  climates  of  the  State,  and 
the  best  methods  of  starting  and  grafting  a  resistant  vineyard. 

With  regard  to  the  first  phase,  the  Station  is  carrying  on  tests  in 
various  localities  and  is  gradually  accumulating  data  which  will  make 
it  possible  to  offer  some  definite  recommendations  at  a  future  time. 
The  questions  of  adaptation  to  local  conditions  and  of  affinity  between 
stocks  and  scions  of  various  varieties  are  complicated  and  difficult,  and 
require  much  time  and  experimentation  for  their  completely  satisfac- 
tory solution. 

With  regard  to  the  second  phase  we  have  a  great  deal  of  valuable 
evidence  drawn  from  the  experience  of  growers  during  the  last  twenty 
years  and  from  experiment  work  conducted  by  the  Station.  Though 
there  is  always  room  for  improvement,  we  may  say  that  the  methods 
of  our  most  progressive  growers  of  resistant  vineyards  are  perfectly 
successful  in  accomplishing  the  object  in  view.  Unfortunately  many 
growers  are  not  so  successful,  and  many  of  the  resistant  vineyards  of 
the  State  are  an  eyesore  and  a  source  of  loss  to  their  owners.  It  is  from 
such  growers  that  originates  the  statement  that  resistant  vineyards 
are  a  failure.  Growers  who  have  adopted  proper  methods  of  handling 
resistant  vineyards  are  enthusiastic  in  their  praise.  It  has  been  demon- 
strated here,  as  in  Europe,  that,  as  a  rule,  vineyards  of  vinifera  vines 


90  UNIVERSITY  OF   CALIFORNIA — EXPERIMENT  STATION. 

grafted  on  resistant  stock,  when  properly  handled,  produce  larger  crops 
of  better  grapes  than  vineyards  of  ungrafted  vinifera. 

This  bulletin  is  issued,  therefore,  with  the  object  of  describing  what 
seem  to  us  the  best  methods  of  procedure,  especially  as  regards  the 
mechanical  details  of  grafting,  planting,  and  nursery  work. 

Some  of  the  chief  causes  of  failure  in  unsuccessful  grafted  vineyards 
are: 

1.  The  use  of  a  resistant  variety  which  is  unsuited  to  the  soil  and 
climate  of  the  locality.    Resistant  varieties  are  all  derived  from  one  of 
several  species  of  wild  vines  indigenous  to  the  United  States  east  of  the 
Rocky  Mountains.    All  these  species  are  much  more  difficult  to  suit  in 
the  matters  of  soil  and  climate  than  the  European  wild  vine,   Vitis 
vinifera,  from  which  all  our  wine  and  raisin  and  most  of  our  table 
grapes  are  derived.     This  question  of  adaptation  to  local  conditions  is 
only  touched  on  here. 

2.  The  use  of  an  insufficiently  resistant  variety.     Varieties  of  all 
degrees  of  resistance  exist,  from  almost  absolute  immunity  to  a  degree 
of  resistance  so  small  as  to  be  of  little  practical  value.     Some  with  a 
medium  degree  of  resistance,  like  the  Lenoir,  will  give  fair  to  good 
results  when  grown  under  the  most  favorable  conditions,  but  fail  more 
or  less  completely  when  attacked  by  phylloxera  under  less  favorable 
conditions.    This  question  of  resistance  is  not  discussed  fully  here,  but 
all  the  varieties  recommended  have  sufficient  resistance  under  prac- 
tically all  conditions  that  exist  in  Californian  grape-growing  districts. 

3.  The  use  of  unselected  resistants.    Many  of  the  first  resistant  vine- 
yards started  in  California  were  planted  with  cuttings  of  wild  Riparia 
vines  collected  in  Nebraska  and  other  native  habitats  of  the  species. 
Wild  vines  are  nearly  always  seedlings  and,  therefore,  vary  very  much. 
Each  vine,  though  of  the  same  wild  species,  is  in  fact  a  different  variety 
of  the  species  (using  the  word  variety  in  the  horticultural  sense).    For 
this  reason,  wild  vines  differ  greatly  in  many  respects,  and  especially 
in  the  important  character  of  vigor.     Though  a  few  of  them  may  be 
sufficiently  vigorous  to  make  good  grafting  stock,  many  of  them  are 
much  too  weak  or  slender,  and  none  of  them  are  likely  to  be  as  good  as 
the  best  named  varieties  which  have  been  selected  from  a  vast  number 
of  seedlings  on  account  of  their  exceptional  vigor  and  the  possession  of 
the  greatest  number  of  those  characteristics  which  are  desirable  in  a 
grafting  stock.     Most  of  the   earlier  resistant  vineyards   show   great 
variation  in  the  vigor  and  bearing  of  the  vines  due  to  this  use  of  wild 
cuttings,  and  none  of  them  give  as  good  results  as  they  would  have 
given  if  grafted  on  a  good  selected  variety  of  stock.     This  variation 
in  vigor,  bearing,  and  longevity  is  often  found  in  more  modern  vine- 
yards, and  is  due  to  a  mixing  of  varieties  by  the  nurseryman  or  the 
grower  of  resistant  cuttings. 


RESISTANT   VINEYARDS— GRAFTING,    PLANTING,    CULTIVATION.  91 

4.  Grafting  the  resistant  vines  when  too  old.    A  grafted  vine  to  be 
a  permanent  success  must  have  a  perfect  union.     The  younger  the 
tissues,  the  more  complete  and  lasting  the  union.    Budding  and  graft- 
ing herbaceous  canes  produce  unions  which  are  practically  perfect.    If 
the  scion  and  stock  are  each  only  one  year  old,  as  in  cutting  grafting, 
the  union  is  nearly  always  as  perfect  and  permanent.    No  wood  older 
than  one  year  is  ever  used  as  a  scion,  but  the  stock  is  often  grafted 
when  much  older.    If  the  stock  is  more  than  one  year  old  many  varie- 
ties fail  to  give  good  unions,  and  if  three  or  four  years  old  a  large 
number  of  the  grafted  vines  will  fail  after  they  have  produced  a  few 
crops.     Some  of  the  best  resistant  stocks  fail  almost  completely  if 
grafted  when  several  years  old,  and  though  they  bear  well  and  appear 
strong  for  a  few  years  they  soon  begin  to  fail,  and  every  year  after 
the  first  two  or  three  crops  a  certain  proportion  of  the  unions  fail  and 
the  tops  die.    A  vineyard  may  linger  in  this  way  for  eight  or  ten  years, 
until  finally  from  50  to  75  per  cent  of  the  vines  are  dead.    This  is  one 
of  the  strongest  objections  to  field  grafting,  and  is  more  thoroughly 
discussed  later. 

5.  Planting  or  grafting  too  deep.    The  result  of  this  is  that  the  scions 
form  their  own  roots  and  finally  become  independent  of  the  resistant 
stock,  which  dies.    Such  vines  are,  of  course,  non-resistants  and  just  as 
quickly  killed  by  phylloxera  as  if  grown  in  the  first  place  from  vinifera 
cuttings.     Some  vine-growers,  of  long  experience  with  vinifera  vine- 
yards but  unfamiliar  with  resistants,  do  not  believe  that  this  death  of 
the  resistant  stock  will  take  place  under  the  conditions  described.    They 
state  that  it  is  an  advantage  for  the  scion  to  have  its  own  roots  as 
well  as  those  of  the  resistant.     They  argue  that,  if  there  is  little  or  no 
phylloxera  present,  the  vines  will  do  better  with  two  sets  of  roots  than 
with  one,  and  that,  when  the  phylloxera  increases  to  dangerous  propor- 
tions and  destroys  the  vinifera  roots,  the  resistant  roots  are  there  to 
save  the  vine. 

This  theory  is  based  on  the  false  assumption  that  the  roots  are  the 
main,  or  only,  feeding  organs  of  a  plant,  and  overlooks  the  fact  that 
the  roots  require  the  materials  furnished  by  the  leaves  quite  as  much  as 
the  leaves  require  those  furnished  by  the  roots.  For  both  to  be  vigorous, 
therefore,  there  must  be  a  mutual  exchange  of  food  matters. 

This  exchange  takes  place  through  the  medium  of  the  tubes  and 
cells  of  the  wood  and  bast  of  the  stem  of  the  vine.  The  soil  nutrients 
pass  with  the  sap,  principally  through  the  younger  wood,  from  the  roots 
to  the  leaves.  In  the  leaves  these  materials  are  combined  with  -gases 
absorbed  from  the  air  and  are  elaborated  into  the  real  food  of  the  vine 
which  passes  back,  principally  through  the  bast  or  region  exterior  to  the 
wood,  into  all  parts  of  the  plant,  to  supply  the  material  necessary  for 
growth  and  other  various  vital  functions. 


92 


UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 


In  ungrafted  vines  this  exchange  takes  place  readily  and  all  the 
branches  and  all  the  roots  are  well  nourished.  In  grafted  vines,  owing 
to  the  fact  that  the  stock  and  scion  are  of  different  species  and,  there- 
fore, of  different  structure  and  composition,  there  is  some  interference 
with  the  exchange,  resulting  in  a  slight  weakening  of  the  whole  vine. 
This  weakening,  under  proper  conditions,  is  so  slight  that  it  does  not 


FIG.  1.    Showing  effect  on  Resistant  Stock  of  allowing  the  scion  roots  to  remain. 
(Redrawn  after  Viala  and  Ravaz.) 

A.  Old  grafted  vine  with  large  top  roots  (S)  from  scion.    Note  small,  weak  resistant  stock  (R). 

B.  Normal  grafted  vine  on  which  no  scion  roots  have  been  allowed  to  develop.    Note  smooth 

union  (U)  and  strong  resistant  stock  (R). 

detract  from  the  usefulness  of  the  vine,  and,  in  fact,  like  many  other 
slightly  weakening  causes,  it  usually  has  the  effect  of  producing  an 
increased  tendency  to  fruitfulness.  If,  however,  the  scion  is  allowed  to 
make  its  own  roots,  the  return  stream  of  nutritive  material  takes  the 
course  of  least  resistance  and  goes  principally  into  the  scion  roots.  The 
result  is  that  these  grow  vigorously,  so  long  as  the  phylloxera  is  absent, 
and  the  roots  of  the  resistant  stock  are  starved  and  finally  die.  This 


RESISTANT    VINEYARDS— GRAFTING,    PLANTING,    CULTIVATION.  93 

is  not  mere  theory,  but  is  substantiated  by  the  numerous  cases  where 
dying  resistant  vineyards  have  been  examined  and  this  condition  found. 
This  condition  is  particularly  common  with  field-grafted  vines. 

There  are  several  ways  in  which  the  union  between  resistant  stock 
and  bearing  scion  can  be  brought  about:  (1)  The  scion  cuttings  may 
be  grafted  on  the  resistant  cuttings  or  on  resistant  roots  in  the  work- 
shop before  planting  in  the  nursery.  This  is  called  "bench  grafting." 
(2)  The  resistant  cuttings  may  first  be  rooted  in  the  nursery  and  then 
the  next  year  grafted  in  place  without  removal.  This  is  called  "nursery 
grafting."  (3)  The  resistant  cuttings  or  roots  may  be  planted 
directly  in  the  vineyard  and  then  the  next  year  or  some  subsequent 
year  they  may  be  grafted.  This  is  called  "field  grafting,"  "vineyard 
grafting,"  or  "grafting  in  situ." 

Each  method  has  its  advocates  and  its  uses,  but  the. method  of  most 
general  application  and  that  which  has  given  the  most  general  satisfac- 
tion is  the  first.  The  last  method  is  practised  with  success  only  where 
the  conditions  are  exceptionally  favorable,  and  even  there  is  gradually 
being  rejected  in  favor  of  the  first  by  nearly  every  grower  who  has 
tried  both  methods.  The  reasons  for  this  will  be  discussed  after  the 
various  methods  have  been  described. 


I.    THE  NURSERY. 

Choice  and  Preparation  of  the  Soil.— The  high  cost  of  grafted  vines 
is  due  partly  to  the  skill  and  labor  necessary  in  producing  them,  but, 
also,  in  a  great  degree,  to  the  large  number  of  grafts  which  fail  to  grow 
or  to  make  a  satisfactory  union  in  the  nursery.  If  we  allow  $10  per 
thousand  for  the  cuttings  used  as  stock  and  scion,  and  $15  per  thousand 
for  making  and  growing  the  grafts,  they  could  be  raised  profitably  for 
$35  per  thousand  if  every  one  grew  and  made  a  good  grafted  vine. 
Probably  on  the  average  not  more  than  fifty  per  cent  of  the  grafts  made 
are  sufficiently  perfect  in  growth,  union,  and  root  to  be  sold,  and  they 
must  therefore  bring  $60  or  more  per  thousand  to  be  raised  at  a  profit. 

While  there  are  many  causes  for  the  failure  of  some  of  the  grafts  to 
grow,  probably  the  most  important  of  these  is  the  nature  of  the  soil 
in  which  they  are  rooted.  Any  soil  which  bakes  on  the  top  after  rain 
or  irrigation  will  cause  the  failure  of  many  grafts.  If  the  crust  is  not 
broken  up,  the  moisture  will  escape  and  the  scions  dry  out.  If  the 
crust  is  broken,  many  of  the  scions  will  be  disturbed  and  fail  to  unite. 
A  soil  which  becomes  very  compact  will  spoil  many  grafts  by  preventing 
the  shoot  from  pushing  its  way  through.  Stony  soils  destroy  many 
grafts  in  similar  ways.  If  the  soil  dries  out  too  easily  and  quickly  many 
scions  will  fail  to  unite.  Wet  soils  are  even  worse.  A  soil  which  remains 


•94  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

cold  and  wet  for  any  considerable  time  after  the  grafts  are  planted  will 
cause  the  loss  of  a  large  proportion. 

The  ideal  soil  for  a  nursery  of  bench  grafts  is  a  light,  well-drained, 
sandy  loam  containing  an  abundance  of  humus.  It  should  be  carefully 
graded  in  order  to  have  no  low  spots  where  the  water  will  lie  and  drown 
the  grafts,  and  no  high  spots  to  which  it  is  difficult  to  get  the  irrigation 
water. 

The  physical  nature  and  condition  of  the  soil  is  of  more  importance 
than  its  chemical  composition.  The  soil  should  not  be  poor,  but  it  is, 
on  the  other  hand,  not  desirable  that  it  should  be  too  rich.  Grafts 
which  grow  very  large  in  the  nursery  do  not  make  the  best  vines  in 
the  vineyard.  Extra  large  grafts  often  die  the  first  year  after  they 
are  planted  out.  Small  dwarfed  grafts  are  a  year  behind  those  which 
are  well  grown,  and  probably  never  make  profitable  vines.  A  plant  of 
medium  size,  with  good  roots,  perfect  union,  and  a  growth  of  from  15 
to  18  inches,  is  the  best. 

At  least  two  months  before  planting,  the  soil  of  the  nursery  should 
be  thoroughly  prepared.  All  weeds,  stones,  and  rubbish  should  be 
removed  and  the  ground  well  plowed.  Most  soils  should  be  plowed  or 
•subsoiled  to  a  depth  of  at  least  18  inches  in  order  to  aerate  and  pulver- 
ize the  soil  to  promote  quick  rooting.  Unless  the  roots  of  the  stock 
start  almost  as  soon  as  the  buds  of  the  scion,  the  latter  will  dry  out  as 
soon  as  its  little  leaves  begin  to  evaporate  water.  If  the  subsoil  is  clayey 
or  contains  a  great  deal  of  cementing  material,  it  should  not  be 
turned  up. 

Soils  which  are  defective,  if  used  at  all,  should,  of  course,  be  fertilized. 
Any  fertilizer  which  improves  the  texture  of  the  soil  is  to  be  preferred. 
Well-rotted  stable  manure  is  useful,  but  the  best  fertilizer  for  the 
purpose  is  a  good  crop  of  field  peas  or  other  legume  plowed-in  the 
previous  autumn  sufficiently  early  to  insure  its  complete  rotting  before 
planting  time. 

Cutting  Grafts.  Choice  of  Cuttings.— To  obtain  the  best  results, 
ooth  in  the  percentage  and  quality  of  the  grafted  vines  produced  by 
the  nursery  and  in  the  profit  of  the  vineyard  where  they  are  planted, 
great  care  is  necessary  in  the  selection  of  cuttings  for  both  scions  and 
stocks. 

For  scions,  cuttings  should  be  taken  only  from  healthy  vines  which 
are  known  to  have  produced  good  crops.  Cuttings  from  vines  weakened 
by  phylloxera,  root-rot,  or  other  diseases  are  apt  to  be  weak,  soft,  badly 
nourished,  and  incompletely  matured.  Such  cuttings  will  not  give  a 
high  percentage  of  No.  1  grafts,  nor  make  a  profitable  vineyard.  Cut- 
tings showing  signs  of  serious  attacks  of  oidium,  vine-hoppers,  or  other 
fungi  and  insects  should  be  rejected.  The  cuttings  used  should  be  of 


RESISTANT    VINEYARDS— GRAFTING,    PLANTING,    CULTIVATION.  95 

medium  size,  firm,  with  small,  light-colored  pith  and  short  to  medium 
joints.  Very  large  or  very  small  cuttings  do  not  give  the  largest  per- 
centage of  successful  unions,  nor  the  best  vines.  The  best  size  is  about 
one  third  of  an  inch  in  diameter,  though  this  will  vary  somewhat 
according  to  the  variety  of  vine.  Any  cuttings  under  one  quarter  of 
an  inch  or  over  one  half  an  inch  in  diameter  should  not  be  used.  If 
this  rule  is  adopted,  all  buds  from  the  thick  base  of  the  cane  which 
are  apt  to  give  unfruitful  vines,  and  all  buds  from  the  tip  of  the  cane 
which  are  apt  to  be  immature  and  to  give  weak  vines,  will  be  eliminated. 

The  choice  of  cuttings  for  stocks  is  almost  equally  Important.  All 
the  precautions  regarding  the  health  and  maturity  of  the  cuttings  and 
of  the  vines  from  which  they  come  apply  equally  in  this  case.  The 
most  important  point  to  be  observed,  however,  is  that  they  are  unmixed 
and  true  to  name.  If  there  is  a  slight  mixture  of  varieties  in  the  scion 
cuttings  the  error  is  not  quite  so  serious,  as  the  grapes  may  be  nearly 
equally  valuable,  and  at  worst  the  vines  can  be  regrafted.  If  the  stocks 
are  mixed,  however,  there  is  no  easy  way  of  detecting  it,  and  the  result 
will  probably  be  a  vineyard  of  unequal  growth,  in  which  many  of  the 
vines  are  unprofitable. 

There  is  great  danger  of  this  mixing  of  stocks,  for  many  vineyards 
of  mother  vines  in  California  are  badly  mixed  with  many  inferior  kinds 
of  Riparia,  Rupestris,  etc.,  most  of  which  are  valueless  as  grafting  stock. 
The  conditions  in  France  seem  to  be  no  better,  and  the  risk  of  a  mixture 
in  imported  cuttings  is  greater  than  with  the  home-grown,  as  we  have 
no  opportunity  of  verifying  the  mother  vines  and  are  quite  at  the 
mercy  of  the  nurseryman. 

The  size  of  the  stock  cuttings  must,  of  course,  be  the  same  as  that 
of  the  scions,  as  they  have  to  be  accurately  matched. 

The  cuttings  should  be  smooth  and  straight.  Crooks,  curved  cuttings, 
with  large  knots  where  laterals  have  been  removed,  are  much  more 
difficult  to  graft.  It  is  to  be  desired  that  some  one  would  make  a 
business  of  raising  mother  vines  for  the  production  of  cuttings  for 
grafting.  It  would  be  a  profitable  crop,  and  if  properly  looked  after 
would  much  improve  the  quality  and  lessen  the  cost  of  grafted  vines. 

Planting  and  Cultivation  of  Mother  Vines.— In  planting  a  vineyard 
of  resistant  vines  for  the  production  of  cuttings  to  be  used  for  grafting 
it  is  important  that  a  suitable  soil  and  location  be  chosen.  In  order  to 
produce  a  large  crop  of  good  cuttings  the  soil  should  be  naturally  rich 
or  heavily  fertilized.  The  location  should  be  one  in  which  the  wood 
always  ripens  early  and  thoroughly.  Spring  frosts  are  almost  as 
unfavorable  to  the  production  of  good  cuttings  as  of  grapes. 

The  choice  of  varieties  to  plant  will  depend,  of  course,  on  what  the 
market  demands.  If  there  should  be  a  falling  oft  of  the  demand  for 


96  UNIVERSITY  OF   CALIFORNIA — EXPERIMENT   STATION. 

the  kind  planted,  or  an  overproduction,  it  is  always  possible  to  graft  the 
stocks  with  other  varieties  of  resistants  to  meet  the  changed  conditions. 

For  the  best  results  the  land  should  be  given  the  same  careful 
preparation  recommended  for  the  planting  of  grafts.  (See  page  93.) 
All  the  usual  stocks  are  vigorous  growers,  and  as  they  are  planted  in 
fertile  soil  they  should  be  given  plenty  of  space.  A  distance  of  9  feet 
by  9  feet  or  8  feet  by  10  feet  is  quite  close  enough.  This  will  give  about 
500  vines  to  the  acre.  As  a  good  vine  properly  cared  for  should  produce 
150  feet  of  good  wood  for  bench  grafting,  the  product  of  an  acre  would 
be  about  75,000  cuttings. 

The  varieties  of  resistant  stocks  which  will  in  all  probability  be  most 
used  in  California  are  Rupestris  St.  George  (du  Lot),  Riparia  X  Rupes- 
tris  3306,  Riparia  X  Rupestris  3309,  Riparia  Solonis  16.16,  Mourvedre 
X  Rupestris  1202,  Aramon  X  Rupestris  2,  Riparia  gloire,  and  Riparia 
grande  glabre.  These  are  all  varieties  which  have  given  excellent 
results  for  years  in  Europe,  and  have  all  been  tested  successfully  in 
California.  Among  them  are  varieties  suitable  for  nearly  all  the 
vineyard  soils  of  California,  with  perhaps  the  exception  of  some  of 
the  heavier  clays. 

The  only  one  of  these  varieties  which  has  been  planted  extensively 
in  California  is  the  Rupestris  St.  George.  There  can  be  little  doubt, 
however,  that  it  will  fail  to  give  satisfaction  in  many  soils,  and  though 
we  may  not  find  something  better  for  all  our  soils  it  is  probable  that  we 
will  repeat  the  experience  of  Southern  France  and  find  that  in  most 
soils  there  is  some  other  variety  that  gives  better  results.  Without 
attempting  to  describe  these  varieties,  but  to  give  some  idea  of  their 
merits  and  defects  and  of'  the  soils  most  suited  to  each,  the  following 
indications  are  given,  based  principally  on  the  opinions  of  L.  Ravaz 
and  Prosper  Gervais,  and  on  a  still  limited  experience  in  California : 

The  Rupestris  St.  George  is  remarkably  vigorous  and  grows  very 
large,  supporting  the  graft  well  even  without  stakes.  It  roots  easily 
and  makes  excellent  unions  with  most  vinifera  varieties.  It  is  well 
suited  to  deep  soils  where  its  roots  can  penetrate.  Its  defects  are  that 
it  is  very  subject  to  root-rot,  especially  in  moist  soils;  it  suckers  badly 
and  it  suffers  from  drought  in  shallow  soils.  Its  great  vigor  produces 
coulure  with  some  varieties  and  often  necessitates  long  pruning. 

In  moist  or  wet  soils  1616  or  3306  have  given  better  results  in  France 
and  give  indications  of  doing  equally  well  here.  In  drier  soils  3309  will 
probably  be  found  preferable. 

Aramon  Rupestris  No.  2  is  suited  to  the  same  soils  as  Rupestris 
St.  George,  and  does  particularly  well  in  extremely  gravelly  soils.  It 
has  some  of  the  defects  of  the  St.  George  and  is  moreover  more  difficult 
to  graft,  and  its  only  advantage  in  California  is  that  it  is  rather  less 
susceptible  to  root-rot. 


RESISTANT    VINEYARDS— GRAFTING,    PLANTING,    CULTIVATION.  97 

There  are  no  better  resistant  stocks  than  Riparia  gloire  and  Riparia 
grande  glabre,  wherever  they  are  put  in  soils  that  suit  them.  They 
do  well,  however,  only  in  deep,  rich,  alluvial  soils  which  are  neither 
too  wet  nor  too  dry.  Their  grafts  are  the  most  productive  of  all,  and 
ripen  their  grapes  from  one  to  two  weeks  earlier  than  the  grafts  on 
St.  George.  Their  principal  defect  is  that  they  are  very  particular 
as  to  the  soil,  and  they  never  grow  quite  as  large  as  the  scion.  The 
gloire  is  the  most  vigorous,  and  the  difference  of  diameter  is  less  with 
this  variety  than  with  any  other  Riparia. 

The  Mourvedre  X  Rupestris  1202  is  extremely  vigorous,  roots  and 
grafts  easily,  and  is  well  adapted  to  rich,  sandy  and  moist  soils.  In 
drier  and  poorer  soils  its  resistance  is  perhaps  not  sufficient. 

The  most  promising  varieties  for  general  use  at  present  seem  to  be 
the  two  hybrids  of  Riparia  and  Rupestris,  3306  and  3309.  They  have 
great  resistance  to  the  phylloxera,  root  and  graft  almost  as  easily  as  St. 
George,  and  are  quite  sufficiently  vigorous  to  support  any  variety  of 
vinifera.  The  former  is  more  suited  to  the  moister  soils  and  wherever 
there  is  danger  of  root-rot,  and  the  latter  to  the  drier  soils.  In  general, 
they  are  suited  to  a  larger  variety  of  soils  and  conditions  than  perhaps 
any  other  varieties. 

Riparia  gloire  should  be  planted  only  on  rich,  deep  alluvial  soil 
containing  an  abundance  of  plant  food  and  humus,  what  would  be 
called  good  garden  land,  such  as  river  bank  soil  not  liable  to  overflow. 

In  most  other  soils  Riparia  X  Rupestris  3306  is  to  be  recommended, 
except  those  which  are  rather  dry,  where  3309  is  to  be  preferred,  or 
those  which  are  very  wet,  where  Solonis  X  Riparia  1616  is  surer  to 
give  good  results. 

The  methods  of  pruning  and  training  mother  vines  of  resistant 
varieties  will  differ  in  several  important  respects  from  the  methods 
suitable  for  varieties  grown  for  their  fruit.  In  the  latter  case  we 
should  be  careful  to  leave  as  many  fruitful  buds  as  the  vine  can 
utilize;  in  the  former  the  fruit  is  of  no  value,  and  if  any  is  produced 
it  will  be  at  the  expense  of  the  wood.  Our  object  is  to  produce  as  much 
wood  as  possible. 

In  accordance  with  this  idea  the  mother  vines  are  often  pruned  in 
such  a  way  as  to  force  out  each  year  a  growth  of  watersprouts  from 
the  old  wood.  All  the  canes  on  the  vine  are  cut  off  as  close  to  the 
stump  as  possible. 

It  is  doubtful  if  this  is  the  best  way.  So  many  watersprouts  are 
forced  out  that  the  labor  and  care  of  thinning  them  are  expensive. 
If  they  are  not  thinned  there  is  a  large  growth  of  wood,  but  the  canes 
produced  are  short  and  thin,  and,  therefore,  unsuitable  for  grafting 
stock.  If  this  method  is  adopted  from  the  beginning  the  vine  is 


98  UNIVERSITY  OF   CALIFORNIA — EXPERIMENT  STATION. 

reduced  to  a  prostrate  stump,  which  makes  cultivation  difficult,  and  as 
the  vine  becomes  old  it  becomes  full  of  dead  wood  and  difficult  to 
prune. 

A  better  method  is  to  give  the  vine  a  trunk  and  head  exactly  as  in 
pruning  ordinary  vase-formed  vines.  A  trunk  from  15  to  18  inches 
high  and  with  five  or  six  arms  will  make  a  vine  much  easier  to  cultivate 
and  prune  and  at  least  equally  productive  of  good  cuttings.  In 
pruning,  very  short  spurs  are  left,  consisting  simply  of  the  base  bud. 
The  cane  should  be  cut  off  through  the  first  bud  above  the  base  bud. 
This  will  insure  the  starting  of  the  base  bud  and  will  avoid  the  danger 
of  injury  which  occurs  when  the  cut  is  made  too  close  to  the  bud  which 
we  desire  to  have  grow. 

With  this  method  of  pruning  the  arms  will  lengthen  so  slowly  that 
there  will  never  be  occasion  to  cut  them  back.  During  the  spring  and 
early  summer  all  unnecessary  shoots  should  be  removed  in  order  to 
throw  all  the  vigor  of  the  vine  into  those  which  remain. 

A  good,  strong  vine  in  rich  soil  should  produce  from  150  to  300  feet 
of  good  grafting  wood  between  one  quarter  and  one  half  of  an  inch 
in  diameter,  and  a  certain  amount  of  smaller  wood  good  for  rooting. 
Experience  only  will  tell  how  many  shoots  should  be  left  to  a  vine. 
It  will  depend  on  the  age  of  the  vine,  the  variety  and  the  soil.  If  too 
few  are  left  there  is  apt  to  be  too  much  thick  wood  unsuitable  for 
grafting,  especially  with  certain  varieties  such  as  Rupestris  St.  George. 
If  too  many  are  left  there  will  be  too  many  small  cuttings. 

Some  varieties  of  stocks  produce  good  grafting  wood  if  the  canes 
are  allowed  to  grow  over  the  surface  of  the  ground  without  support. 
This  has  a  tendency  with  some  varieties  to  encourage  the  growth  of 
laterals  and  to  make  the  canes  short  and  stocky. 

To  overcome  this  defect  high  poles  are  sometimes  placed  at  each 
vine,  and  the  canes  kept  in  an  upright  position  by  being  tied  to 
these  poles.  The  poles  are  sometimes  15  or  20  feet  high.  This  method 
produces  an  abundance  of  excellent  grafting  cuttings,  but  is  expensive 
and  troublesome.  A  more  practical  method  is  to  put  a  high  stake— 10 
ieet  high  at  the  end  of  each  row  and  to  stretch  a  wire  at  that  height 
along  the  row.  The  shoots  are  then  trained  up  to  this  wire  by  means  of 
strings  renewed  every  year.  (See  Fig.  2.) 

Making  and  Conservation  of  Cuttings.— Cuttings  for  grafting,  to  be 
used  either  as  stocks  or  scions,  may  be  taken  from  the  vines  at  any 
time  between  the  fall  of  the  leaves  in  the  autumn  and  two  weeks  before 
the  swelling  of  the  buds  in  the  spring.  They  may  be  used  as  soon  as 
made,  or  kept  for  an  indefinite  time,  provided  they  are  given  proper 
care. 


RESISTANT    VINEYARDS  — GRAFTING,    PLANTING,    CULTIVATION.  99 

It  is  usually  more  convenient  to  take  the  canes  from  the  vines,  place 
them  in  an  outhouse  or  shed,  and  make  them  up  into  cuttings  in  rainy 
weather.  In  a  shed  they  may  be  left  without  protection  for  a  couple 
of  weeks,  but  it  is  best  not  to  leave  them  longer,  especially  in  dry 
weather. 

The  scion  cuttings  are  conveniently  cut  in  lengths  of  from  18  inches 
to  3  feet,  and  tied  in  bundles  of  100  to  250  if  they  are  to  be  transported 
to  a  distance.  They  should  be  tied  up  in  such  a  way  that  the  butte 
of  all  of  them  are  even ;  this  will  prevent  any  of  them  drying  out  when 


FIG.  2.    Mother  vines  of  resistant  stock.    (From  catalog  of  F.  Richter,  Montpellier.) 


they  are  heeled  in.  If  they  are  to  be  kept  for  grafting  where  cut, 
should  be  made  into  loosely  tied  small  bundles,  which  should  be  well 
covered  with  loose  soil  or  sand,  care  being  taken  to  cause  some  of  the 
sand  to  fall  in  among  the  cuttings  in  the  center  of  the  bundle.  They 
may  be  heeled  in  outside  in  some  place  protected  from  the  sun  and 
from  water.  They  are  safer,  however,  and  will  remain  dormant  longer 
if  placed  in  a  sand  pile  under  a  shed  or  in  an  underground  cellar. 
There  should  be  a  few  inches  of  sand  both  under  and  above  the 
cuttings. 

The  sand  in  which  the  cuttings  are  placed  should  be  fairly  dry.  If 
too  dry  the  cuttings  may  die,  but  the  chief  danger  is  that  it  will  be  too 
wet,  in  which  case  they  will  rot.  The  sand  should  not  contain  more 
than  five  per  cent  of  moisture.  With  less  than  this  amount  it  will  not 


100  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

feel  moist  to  the  hand.  If  a  handful  of  sand  is  taken  it  should  not  form 
o  ball  when  squeezed  and  should  not  leave  the  hand  moist.  There  is 
very  little  danger  of  getting  the  sand  too  dry,  unless  it  is  taken  from 
the  top  of  a  pile  which  has  been  exposed  to  the  hot  sun  for  several 
days.  An  ideal  method  of  keeping  cuttings  is  to  cover  them  with  a 
mixture  of  dry  moss  and  a  little  powdered  charcoal  in  a  cool,  moist 
cellar.  The  cuttings  should  be  loose  or  in  small  bundles  in  order  that 
they  may  all  be  in  contact  with  the  moss. 

Cuttings  to  be  used  as  stocks  should  be  handled  in  the  same  way, 
except  that  it  is  preferable  to  cut  them  up  into  the  lengths  which  will 
be  used.  The  length  will  vary  from  8  to  15  inches,  according  to 
whether  long-  or  short-grafted  plants  are  panted.  For  planting  in 
very  dry  soils  which  are  very  open  and  liable  to  dry  down  deep,  and 
for  hillsides  where  the  unions  must  be  placed  higher,  long  grafts  are 
desirable.  As  a  rule,  a  cutting  of  10  inches  is  quite  long  enough  for 
grafting.  Longer  cuttings  are  more  difficult  to  handle  in  the  nursery, 
and  shorter  cuttings  require  more  care  in  the  vineyard.  The  stock 
cuttings  should  be  kept  dormant  like  the  scions,  but  a  slight  swelling 
of  the  buds  is  not  so  serious  in  this  case.  If  the  scion  buds  have 
commenced  to  swell  they  should  not  be  used,  as  there  will  be  too  many 
fail  to  grow.  If  the  stocks  have  started  a  little  they  can  still  be  used 
successfully,  provided  that  the  bark  has  not  become  loose. 

Time  of  Grafting.— Cutting  grafting  may  be  commenced  in  California 
by  the  first  of  January,  or  even  sooner,  but  the  best  results  are  obtained 
by  grafting  in  February  and  March.  The  work  may  be  continued 
through  April  and  even  in  May  if  the  cuttings  can  be  kept  dormant. 

Preparation  of  Stocks.— The  first  thing  to  do  when  everything  is 
ready  for  grafting  is  to  prepare  the  stocks.  If  it  has  not  already  been, 
done  the  resistant  cuttings  should  be  cut  into  the  desired  lengths — 
say  10  inches.  This  should  be  done  as  accurately  as  possible,  and  some 
kind  of  gauge  will  be  needed.  This  gauge  may  be  simply  marks  cut 
in  the  work  table,  or  a  stick  of  the  required  length  held  in  the  hand. 

The  cut  at  the  bottom  should  be  made  through  a  bud  in  such  a  way 
as  to  leave  the  diaphragm  or  partition  which  interrupts  the  pith  at 
this  place.  The  top  cut  should  then  be  made  as  near  10  inches  from 
the  bottom  as  is  possible,  while  at  the  same  time  leaving  at  least  1% 
inches  of  internode  above  the  top  bud.  This  piece  of  intcrnode  is 
necessary  for  convenience  in  grafting. 

Fig.  3  shows  a  simple  gauge  for  insuring  accuracy  in  cutting  the 
stocks.  It  consists  of  a  piece  of  1-inch  board  18  inches  long  and  6 
inches  wide,  to  the  middle  of  which  is  nailed  a  piece  of  wood  1  inch 


RESISTANT    VINEYARDS  — GRAFTING,    PLANTING,    CULTIVATION.          101 

square  in  section  extending  the  whole  length  of  the  board.  -  The  length 
of  the  stock  is  determined  by  an  adjustable  piece  of  wood  3  inches  long 
placed  at  right  angles  to  the  longitudinal  piece.  A  corner  of  the  board 
opposite  this  adjustable  piece  is  cut  off  in  such  a  way  that  the  outer 
edge  of  the  board  is  1%  inches  shorter  than  the  other  edge.  A  guide 
line  is  then  cut  in  the  board  parallel  with  the  slanting  edge  left  by  the 
saw  and  1%  inches  from  this  edge.  In  using  the  gauge  the  base  of 
the  cutting  is  placed  against  the  adjustable  piece  and  the  cutting  moved 
backwards  or  forwards  until  a  bud  falls  just  to  the  right  of  the  guide 
line.  The  cutting  is  then  cut  off  level  with  the  edge  of  the  board.  This 
gives  each  stock  1%  inches  of  internode  for  grafting  above  the  top 
bud,  with  a  maximum  variation  of  1%  inches  in  total  length.  This 
variation  is  of  little  consequence  and  can  not  be  avoided.  Greater 
variations  give  trouble  in  planting.  Any  inconvenience  due  to  even 


FIG.  3.    Gauge  for  cutting  stocks. 

this  variation  may  be  avoided  by  sorting  the  cuttings  into  two  or  three 
lots  according  to  length  after  cutting,  though  this  sorting  is  perhaps 
best  deferred  until  the  grafts  are  made. 

The  next  process  is  the  disbudding  of  the  stocks.  If  this  is  done 
properly,  it  decreases  greatly  the  number  of  stock  suckers  which  will 
appear  in  the  nursery  and  which  must  be  removed.  With  some  varie- 
ties, such  as  Riparia,  all  that  is  necessary  is  to  cut  out  the  main  bud. 
This  is  most  easily  and  quickly  done  with  a  knife.  With  other  varieties 
such  as  the  Rupestris  St.  George,  it  is  necessary  to  cut  more  deeply  and 
to  remove  not  only  the  main  bud,  but  also  the  woody  enlargement  at 
its  base  containing  a  number  of  dormant  buds  which  readily  give  rise 
to  suckers.  This  is  most  easily  done  with  a  sharp  pair  of  pruning 
shears.  Every  bud  on  the  stock  should  be  removed.  It  is  a  mistake 
to  leave  the  bottom  bud,  as  is  sometimes  done.  This  bud  is  of  no  use,  as 
rooting  takes  place  just  as  well  without  it,  and  if  it  forms  a  sucker, 
this  sucker  is  the  most  troublesome  of  all  to  remove  on  account  of  its 
position. 

'    2— BUL.  180. 


102  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

Preparation  of  Scions.— A  scion  may  consist  of  one  bud  or  of  two 
buds.  There  are  many  advantages  in  using  one  bud,  the  chief  of  which 
is  that  it  makes  it  possible  to  have  every  scion  the  same  length  what- 
ever the  length  of  the  internodes.  With  two-bud  scions  it  is  impossible 
to  avoid  a  difference  of  2  or  3  inches  in  the  length,  owing  to  the  varia- 
tions in  the  distances  between  the  buds.  If  the  scions  are  of  the  same 
length  it  is  possible  to  have  all  the  unions  at  the  same  distance  below 
the  surface  in  the  nursery.  This  is  a  most  important  point.  The  only 
advantage  of  two-bud  scions  is  that  in  ground  which  bakes  on  top  it 
is  possible  to  have  the  top  bud  above  the  surface  of  the  ground  and 
yet  have  the  union  sufficiently  deep  to  prevent  drying  out.  Where  the 
soil  does  not  bake  the  scions  may  be  covered  up  completely  and  one 
bud  is  sufficient. 

The  scions  should  be  cut  with  about  2%  inches  of  internode  below 
the  bud  and  at  least  %  inch  of  internode  above  the  top  bud.  If  cut  too 
close,  especially  with  blunt  pruning  shears,  there  is  danger  of  injuring 
the  bud.  A  sharp  knife  is  the  best  tool  for  cutting  scions. 

Grading  the  Cuttings.— For  the  best  results  the  stock  should  be  of 
exactly  the  same  diameter  as  the  scion.  If  they  differ  much  they  may 
unite,  but  the  union  will  usually  be  imperfect.  The  more  nearly  they 
match  in  size  the  more  perfect  the  unions  and  the  larger  the  percentage 
of  first-class  grafts. 

If  the  cuttings  are  not  sorted  beforehand  the  grafter  loses  a  great 
deal  of  time  in  looking  for  scions  to  fit  his  stocks.  A  good  deal  of  this 
time  may  be  saved  if  the  cuttings  are  sorted  by  eye  into  three  lots- 
large,  medium,  and  small— before  commencing  to  graft.  This  division, 
however,  is  not  fine  enough,  and  the  grafter  will  still  have  to  waste 
much  time  in  selection. 

It  is  not  practicable  to  grade  the  cuttings  more  accurately  than  this 
by  eye,  and  some  mechanical  gauge  or  calibrator  is  necessary  for  greater 
accuracy.  Several  forms  have  been  used  in  practice  with  success. 

The  commonest  form  is  the  notch  grader  shown  at  the  top  of  Fig.  4. 
This  consists  of  a  brass  plate  12  inches  long  and  2  inches  wide,  in 
which  are  made  six  or  more  notches.  Each  of  these  notches  differs? 
from  the  next  nearest  by  one  sixteenth  of  an  inch,  and  they  usually 
vary  from  four  sixteenths,  the  smallest,  to  ten  sixteenths,  the  largest. 
By  the  use  of  this  grader  the  cuttings  may  be  separated  into  eight  or 
more  sizes.  These  sizes  differ  from  each  other  by  the  same  absolute 
amount,  i.  e.,  one  sixteenth  of  an  inch,  but  the  relative  difference  in 
the  smaller  sizes  is  greater  than  in  the  larger  sizes.  That  is  to  say, 
size  No.  1  is  four  sixteenths  of  an  inch  in  diameter,  or  four  fifths  the 
size  of  No.  2,  which  is  five  sixteenths  of  an  inch,  while  size  No.  7  is  ten 
sixteenths  of  an  inch  in  diameter,  or  ten  elevenths  of  size  No.  8.  The 


RESISTANT    VINEYARDS  — GRAFTING,    PLANTING,    CULTIVATION.          103 


greatest  accuracy,  therefore,  is  obtained  where  it  is  least  needed,  viz., 
in  the  larger  sizes. 

To  overcome  this  objection  and  also  to  facilitate  the  work  of  sorting, 
the  slot  grader  shown  at  the  bottom  of  Fig.  4  was  devised  at  the 
Experiment  Station.  This  grader  consists  of  a  brass  plate  in  which 


O 


o 


o 


o 


o 


o 


Sca> 


FIG.  4.    GRADERS. 


Notch  Grader,  above.    Each  notch  is  of  the  width  indicated  by  the  corresponding  number, 
which  represents  sixteenths  of  an  inch. 
Slot  Grader,  below.    Width  of  slot  at  e,  %  inch;  at  a,  j  inch.    Length  of  slot  from  e  to  a,  7  inches. 

is  cut  a  tapering  slot  terminated  at  each  end  by  circular  enlargements* 
Fig.  4  shows  the  exact  dimensions  and  Fig.  5  the  general  appearance 
of  the  grader.  The  brass  plate  is  screwed  on  to  a  wooden  block  in 
which  is  cut  a  groove  three  fourths  of  an  inch  deep  and  corresponding 
to  the  slot  in  the  plate.  The  cuttings  are  graded  by  inserting  the  end 


FIG.  5.    Slot  grader  mounted  on  a  wooden  block. 

which  is  to  be  grafted  in  the  wide  end  of  the  slot  and  then  passing  it 
along  the  slot  until  it  can  go  no  farther.  Cuttings  over  one  half  of  an 
inch  in  diameter  will  not  enter  the  slot,  while  those  under  one  fourth  of 
an  inch  will  pass  completely  through.  Cuttings  of  dimensions  between 
these  two  extremes  will  stop  the  nearer  the  large  end  of  the  slot  the 
thicker  they  are.  In  order  to  grade  them  into  various  sizes,  therefore, 
all  that  is  necessary  is  to  mark  lines  on  the  brass  plate,  or,  better,  on 


104 


UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 


the  top  of  the  wooden  block,  and  to  sort  them  into  boxes  according  to 
the  position  in  the  slot  where  they  come  to  rest.  The  nearer  we  place 
the  lines  the  more  grades  of  cuttings  we  will  have  and  the  less  varia- 
tion there  will  be  in  each  grade.  Fig.  6  shows  the  various  positions 
of  the  lines  to  make  four,  five,  or  six  grades  of  the  cuttings  between 
14  and  %  inch  in  diameter.  To  construct  the  grader  the  only  measure- 
ments needed  are  the  length  from  a  to  e  (1  inches)  and  the  width  at  e 
(1/2  inch)  and  at  a  (^  inch). 

The  scale  can  be  cut  with  a  chisel  on  the  block  and  the  place  of  the 
lines  determined  with  sufficient  accuracy  by  means  of  a  rule  showing 
tenths  of  an  inch.  The  distances  between  the  lines  of  the  three  scales 
have  been  calculated  in  such  a  way  that  each  size  bears  a  certain  ratio 
to  the  one  next  to  it.  The  ratios  used  are  .8409,  .8705,  and  .8909, 
respectively.  This  means  that  if  we  use  the  first  scale  each  grade  of 
cuttings  will  average  almost  exactly  five  sixths  of  the  diameter  of  the 
next  larger  size.  With  the  second  scale  the  difference  will  be  seven 
eighths,  and  with  the  third  eight  ninths.  Or,  looking  at  it  another 
way,  it  means  that  the  cuttings  in  one  grade  will  not  vary  more  than 
as  5 :  6  in  the  first  case,  7 :  8  in  the  second,  and  8 :  9  in  the  third. 

The  following  table  shows  the  average  diameters  of  the  several 
grades  (see  Fig  6)  : 


SCALIC  T. 

SCALE  11. 

SCALE  III. 

.250  in. 

Size  1  less  than 

.250  in. 

Size  1  less  than 

.250  in. 

Size  1  less  than 

Size  2  average 
Size  3  average 
Size  4  average 
Size  5  average 

.274  in. 
.325  in. 
.387  in. 
.460  in. 

Size  2  average 
Size  3  average 
Size  4  average 
Size  5  average 
Size  6  average 

.269  in. 
.309  in. 
.354  in. 
.407  in. 
.468  in. 

Size  2  average 
Size  3  average 
Size  4  average 
Size  5  average 
Size  6  average 
Size  7  average 

.265  in. 
.298  in. 
.334  in. 
.375  in. 
.426  in. 
.478  in. 

Size  6  more  than 

.500  in. 

Size  7  more  than 

.500  in. 

Size  8  more  than 

.500  in. 

If  the  grader  is  used  according  to  the  directions  given  below  the 
cuttings  will  be  sorted,  if  scale  I  is  used,  into  six  sizes.  The  largest  of 
these  will  be  over  %  inch  and  the  smallest  under  %  inch  5  these  should 
be  rejected.  The  intermediate  will  then  fall  into  four  sizes,  which  will 
have  the  following  diameters  indicated  in  the  table : 

Average  Extreme 

Diameter.  Variation. 

Size    2 2736  in.  .0473 

Size    3 3254  in.  .0562 

Size    4 3870  in.  .0670 

Size    5 4603m.  .0795 

These  sizes  differ  from  each  other  in  such  a  way  that  the  average 
diameter  of  each  is  almost  exactly  five  sixths  of  that  of  the  next  larger 


O 


Q) 


Q) 


106  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

size.  Or,  looking  at  it  another  way,  the  smallest  cutting  in  any  grade 
is  just  five  sixths  of  the  diameter  of  the  largest  cutting  of  the  same 
grade. 

The  green  bark  or  growing  layer  on  small  cuttings  is  thinner  than  that 
on  large  cuttings,  but  in  all  it  is  just  about  one  sixth  of  the  diameter  of 
the  whole.  If,  therefore,  the  smallest  scion  of  any  grade  is  grafted  on 
the  largest  stock  of  the  same  grade  the  outer  edge  of  the  bark  of  the 
scion  will  be  in  contact  with  the  inner  edge  of  the  bark  of  the  stock. 
This  brings  the  growing  layers  sufficiently  near  to  insure  the  formation 
of  a  good  union.  This,  moreover,  is  an  extreme  case ;  the  great  majority 
of  the  grafts  will  fit  much  more  nearly  than  this. 

Comparing  these  results  with  those  obtained  with  the  notch  grader  it 
will  be  seen  that  the  cuttings  between  %  incn  and  %  inch  are  sorted 
into  only  four  sizes  with  the  slot,  while  the  notches  make  five  sizes 
of  the  same  cuttings.  This  reduction  of  the  number  of  sizes  is  of  some 
practical  advantage,  especially  as  there  is  no  loss  of  accuracy,  but 
rather  a  gain,  as  the  smallest  sizes  vary  only  as  5 :  6,  while  those  of  the 
notch  grader  vary  as  4 :  5. 

A  practised  workman  will  grade  almost  as  quickly  with  a  notch 
grader  as  with  the  slot,  but  in  the  hands  of  a  beginner  the  latter  is 
much  more  rapid  and  accurate. 

Four  grades  is  the  least  number  that  should  be  made  of  cuttings 
between  %  inch  and  ^2  inch.  With  this  number  some  of  the  cuttings 
will  not  fit  exactly  enough  to  satisfy  some  grafters,  and  a  little  eye 
sorting  may  have  to  be  done  while  grafting.  This  sorting  by  the 
grafter  consumes  a  great  deal  of  valuable  time,  and  it  is  better  to  use 
a  more  closely  graduated  scale  if  the  first  does  not  give  satisfaction. 
The  third  scale  is  sufficiently  close  to  satisfy  the  most  particular. 

In  using  the  grader,  every  cutting  should  be  measured  through  its 
longest  diameter  or  much  of  the  accuracy  of  the  sorting  will  be  lost. 
The  flattening  is  always  on  the  side  toward  which  the  bud  points,  so 
that  the  longest  diameter  is  that  at  right  angles  to  the  one  passing 
through  the  bud.  In  using  the  slot  grader,  therefore,  the  cutting 
should  always  be  held  with  the  bud  pointing  horizontally. 

Advantage  may  be  taken  of  the  difference  in  the  two  diameters  to 
compensate  for  the  variation  in  size  of  cuttings  in  the  same  grade.  As 
the  cuttings  vary  as  5 :  6  and  the  two  diameters  vary  in  about  the  same 
ratio,  the  smallest  scion  cut  on  the  flat  side  will  fit  accurately  the 
largest  stock  cut  on  the  narrow  side.  The  only  consequence  is  a  slight 
angle  at  the  point  of  union,  as  shown  in  Fig.  7,  D  1  and  3. 

Methods  of  Uniting  Stock  and  Scion.— Innumerable  methods  of 
cutting  and  splitting  the  stocks  and  scions  have  been  described  and 
recommended.  "We  will  have  little  difficulty  in  choosing  the  best  of 


FIG.  7.    THREE  METHODS  OF  BENCH-GRAFTING  CUTTINGS. 


108  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

these  if  we  remember  the  fact  that  any  method  which  brings  the  grow- 
ing layers  of  the  two  parts  of  the  graft  into  juxtaposition  and  keeps 
them  there  firmly  until  they  unite  will  give  good  results.  Among  those 
which  fulfill  these  conditions  the  best  will  be  those  which  mutilate  the 
tissues  least,  leave  the  least  amount  of  cut  surfaces  exposed,  and  are  the 
most  easily  and  rapidly  performed. 

These  considerations  restrict  our  choice  in  bench  grafting  vines  by 
hand  to  two  methods — the  tongue,  whip,  or  English  cleft,  and  the  wire- 
graft. 

Tongue  Grafting. — When  the  stocks  and  scions  are  prepared  and 
graded  the  grafter  takes  a  box  of  stocks  and  a  box  of  the  corresponding 
size  of  scions  and  unites  them.  Each  is  cut  at  the  same  angle  in 
such  a  way  that  when  placed  together  the  cut  surface  of  one  exactly 
fits  and  covers  the  whole  of  the  cut  surface  of  the  other.  (See  Fig.  7, 


FIG.  H.    Showing  method  of  holding  the  knife  and  cutting. 

A  1.)  The  length  of  cut  surface  should  be  from  three  to  four  times 
the  diameter  of  the  cutting,  the  shorter  cut  for  the  larger  sizes  and  the 
longer  for  the  thinner.  This  will  correspond  to  an  angle  of  from,  14.5 
to  19.5  degrees.  The  cut  should  be  made  with  a  sliding  movement  of 
the  knife,  as  illustrated  in  Fig  8.  This  will  make  the  cut  more  easily 
and  more  smoothly. 

The  cut  should  be  made  with  a  single  quick  motion  of  the  knife.  If 
the  first  cut  is  not  satisfactory,  a  completely  new  one  should  be  made. 
There  should  be  no  paring  of  the  cut,  as  this  will  make  an  irregular 
or  wavy  surface  and  prevent  the  cuttings  coming  together  closely  in 
all  parts. 

The.  tongues  are  made  with  a  slow,  sliding  motion  of  the  knife.  They 
are  commenced  slightly  above  one  third  of  the  distance  from  the  sharp 
end  of  the  bevel  and  cut  down  until  the  tongue  is  just  a  trifle  more  than 
one  third  the  length  of  the  cut  surface.  The  tongue  should  be  cut, 
not  split.  The  knife  should  not  follow  the  grain  of  the  wood,  but 
should  be  slanted  in  such  a  way  that  the  tongue  will  be  about  one 
half  as  thick  as  it  would  be  if  made  by  splitting.  Before  withdrawing 


RESISTANT    VINEYARDS— GRAFTING,    PLANTING,    CULTIVATION.         109 

the  knife  it  is  bent  over  in  order  to  open  out  the  tongue.  This  very 
much  facilitates  the  placing  together  of  stock  and  scion.  (See  Fig.  7, 
A  2,  3.) 

The  stock  and  scion  are  now  placed  together  and,  if  everything  has 
been  done  properly,  there  will  be  no  out  surface  visible  and  the 
extremity  of  neither  stock  nor  scion  will  project  over  the  cut  surface 
of  the  other.  (See  Fig.  7,  A  4.)  It  is  much  better  that  the  points 
should  not  quite  reach  the  bottom  of  the  cut  surface  than  that  they 
should  overlap,  as  the  union  will  be  more  complete  and  the  scions  will 
be  less  liable  to  throw  out  roots.  If  the  points  do  overlap,  the  over- 
lapping portion  should  be  cut  off,  as  in  the  Champin  grafts.  (See 
Fig.  7,  C.) 

A  skillful  grafter,  by  following  the  above-described  method,  will 
make  grafts  most  of  which  will  hold  together  very  firmly.  Many  of 
them  would  fae  displaced,  however,  in  subsequent  operations,  so  that 
it  is  necessary  to  tie  them.  This  is  done  with  raffia  or  waxed  string. 
The  only  object  of  the  tying  is  to  keep  the  stock  and  scion  together 
until  they  unite  by  the  growth  of  their  own  tissues,  so  that  the  less 
material  used  the  better,  provided  this  object  is  attained.  For  the 
formation  of  healing  tissue  air  is  necessary,  so  that  clay,  wax,  tinfoil, 
or  anything  that  would  exclude  the  air  should  not  be  used.  The  tying 
material  is  passed  twice  around  the  point  of  the  scion  to  hold  it  down 
firmly,  and  then  with  one  or  two  wide  spirals  it  is  carried  to  the  point 
of  the  stock,  which  is  fastened  firmly  with  two  more  turns  and  the 
end  of  the  string  passed  under  the  last  turn.  The  less  string  is  used 
the  more  easily  it  is  removed  later  in  the  nursery.  (See  Fig.  7,  A  5 
and  C  5.) 

Untreated  raffia  should  be  used  for  late  grafts  which  are  to  be 
planted  directly  out  in  the  nursery,  but  if  the  grafts  are  to  be  placed 
first  in  a  callusing  bed  it  is  best  to  bluestone  the  raffia  in  order  to 
prevent  rotting  before  the  grafts  are  planted.  This  is  done  by  steep- 
ing the  bundles  of  raffia  in  a  three  per  cent  solution  of  bluestone  for 
a  few  hours  and  then  hanging  them  up  to  dry.  Before  using,  the 
raffia  should  be  washed  quickly  in  a  stream  of  water  in  order  to 
remove  the  bluestone  which  has  crystallized  on  the  outside  and  which 
might  corrode  the  graft. 

Some  grafters  prefer  waxed  string  for  grafting.  The  string  should 
be  strong  enough  to  hold  the  graft,  but  thin  enough  to  be  broken  by 
hand.  No.  18  knitting  cotton  is  a  good  size.  It  is  waxed  by  soaking 
the  balls  in  melted  grafting  wax  for  several  hours.  The  string  will 
absorb  the  wax,  and  may  then  be  placed  on  one  side  until  needed.  A 
good  wax  for  this  purpose  is  made  by  melting  together  one  part  of 
tallow,  two  parts  of  beeswax,  and  three  parts  of  rosin. 


110 


UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 


Wire  Grafting. — The  merits  claimed  for  this  method  are  that  it 
is  more  rapid,  requires  less  skill,  and  does  away  with  the  troublesome 
tying  and  still  more  troublesome  removal  of  the  tying  material.  Prac- 
tised grafters  can  obtain  as  large  a  percentage  of  No.  1  unions  by  this 
method  as  by  any  other,  and  unpractised  grafters  can  do  almost  as 


FIG.  9.    Wire-cutter. 

well  as  practised.    Another  advantage  of  the  method  is  that  the  scions 
have  less  tendency  to  make  roots  than  with  the  tongue  graft. 

It  consists  essentially  of  the  use  of  a  short  piece  of  galvanized  iron 
wire  inserted  in  the  pith  of  stock  and  scion  for  the  purpose  of  holding 
them  together,  thus  replacing  both  tongues  and  raffia.  It  has  been 
objected  that  the  iron  would  have  a  deleterious  effect  on  the  tissues 
of  the  graft,  corroding  them,  or  causing  them  to  decay.  There  seems, 
however,  no  reason  to  expect  any  such  result,  and  vines  grafted  in  this 
way  have  been  bearing  for  years  without  showing  any  such  effect. 


RESISTANT    VINEYARDS  — GRAFTING,    PLANTING,    CULTIVATION.          Ill 

The  preparation  and  grading  of  stocks  and  scions  are  exactly  the 
same  for  this  method  as  for  the  tongue  graft. 

Stock  and  sqion  are  cut  at  an  angle  of  45  degrees.  (See  Fig.  7,  B  1.) 
A  piece  of  galvanized  iron  wire  two  inches  long  is  then  pushed  one 
inch  into  the  firmest  pith.  (See  Fig.  7,  B  2.)  This  will  usually  be 
the  pith  of  the  stock,  but  it  will  depend  on  the  varieties  being  grafted. 
The  scion  is  then  pushed  on  to  the  wire  and  pressed  down  until  it  is  in 
contact  with  the  stock.  (See  Fig.  7,  B  3,  5.)  If  the  cuttings  have 


FIG.  10.    Stand  for  making  bundles. 

large  pith  it  is  better  to  use  two  pieces  of  wire,  one  placed  in  the  stock 
first  and  the  other  in  the  scion,  as  shown  in  Fig.  7,  B  4. 

The  length  of  wire  to  use  will  vary  with  the  size  and  firmness  of  the 
cuttings,  but  2  inches  will  usually  be  found  most  satisfactory.  Wire 
of  No.  17  gauge  is  the  most  useful  size.  Fig.  9  shows  a  device  for 
rapidly  cutting  up  the  wire  into  the  desired  lengths. 

Making  Bundles.— It  the  grafts  are  to  be  planted  out  directly  in 
the  nursery  they  may  be  simply  laid  in  boxes  or  trays,  covered  with 
damp  sacks,  and  carried  out  to  be  planted  as  soon  as  made.  It  is 
usually  better,  however,  to  place  them  for  several  weeks  in  a  callusing 
bed  before  planting.  In  this  case  it  is  necessary  for  convenience  of 
handling  to  tie  them  up  into  bundles.  No  more  than  twenty  grafts 


112  UNIVERSITY  OP   CALIFORNIA — EXPERIMENT  STATION. 

should  be  placed  in  a  bundle,  and  ten  is  better.  If  the  bundles  are 
too  large  there  is  danger  of  the  grafts  in  the  middle  becoming  moldy 
or  dry. 

A  stand  similar  to  that  shown  in  Fig.  10  is  very  convenient.  It 
consists  of  a  piece  of  board  12  inches  by  6  inches,  on  one  end  of 
which  is  nailed  a  cleat  6  inches  by  4  inches  and  under  the  other  end 
a  support  of  the  same  size.  Two  4-inch  wire  nails  are  driven  through 
the  board  from  below,  4  inches  apart  and  5  inches  from  the  cleat.  Two 
other  4-inch  nails  are  driven  similarly  at  1%  inches  from  the  other 
end.  The  grafts  are  laid  on  this  stand  with  the  scions  resting  against 
the  cleat,  and  are  then  tied  with  the  two  pieces  of  bluestoned  raffia 
that  have  previously  been  placed  above  each  pair  of  nails.  This 
arrangement  insures  all  the  scions,  and  therefore  the  unions,  being  at 
the  same  level,  and  puts  both  ties  below  the  union  where  they  will  not 
strain  the  graft.  The  tying  is  more  expeditious  and  less  liable  to 
disturb  the  unions  than  if  the  bundles  are  made  without  a  guide. 

A  skillful  grafter  will  make  about  one  hundred  tongue  grafts  on 
cuttings  per  hour,  or  from  sixty-five  to  seventy-five  per  hour  if  he  does 
the  tying  as  well.  Wire  grafts  can  be  made  at  the  rate  of  two  hundred 
and  fifty  or  more  per  hour,  and  by  proper  division  of  labor  where  several 
grafters  are  employed  this  number  can  be  easily  exceeded.  These  esti- 
mates do  not  include  the  preparation  and  grading  of  the  cuttings. 

Grafting  Rooted  Cuttings.— Instead  of  grafting  cutting  on  cutting 
before  rooting,  one  may  graft  a  scion  cutting  on  a  stock  cutting  which 
has  been  rooted  in  the  nursery  the  previous  season.  In  this  way  resistant 
cuttings  which  are  too  small  to  graft  become  large  enough  the  following 
year  and  may  be  utilized.  The  principal  use  of  this  method,  however, 
is  in  producing  grafts  on  stocks  which  root  with  difficulty,  such  as 
Lenoir  and  Berlandieri.  If  we  make  cutting  grafts  on  these  varieties 
the  percentage  of  successes  is  extremely  small,  on  account  of  the  large 
number  which  fail  to  root.  They  unite  easily,  however,  with  the  scion, 
so  that  if  we  defer  the  grafting  until  the  stock  has  rooted  we  save 
the  expense  of  making  a  large  number  of  grafts  which  never  grow. 

With  cutting  grafts  on  stocks  such  as  Riparia  and  Rupestris  from 
50  to  60  per  cent  of  No.  1  unions  is  considered  an  excellent  average. 
With  rooted  stocks  the  average  should  be  from  75  to  80  per  cent  with 
nearly  all  stocks.  The  former  method  is  preferable,  however,  wherever 
practicable,  as  a  whole  year  is  saved  and  the  unions  on  the  whole  are 
better. 

The  same  methods,  tongue  or  wire  graft,  may  be  used  with  rooted 
stocks  as  with  cuttings.  The  only  difference  lies  in  the  preparation 
of  the  stocks.  The  stocks  are  cut  down  to  a  uniform  length  as  nearly 
as  possible  and  the  scions  inserted  on  the  original  cutting.  The  scion 


RESISTANT    VINEYARDS  — GRAFTING,    PLANTING,    CULTIVATION.          113 

should  not  be  grafted  on  to  the  growth  of  the  previous  season,  even 
when  it  is  large  enough,  as  the  numerous  suckers  which  would  be  pro- 
duced would  be  very  troublesome  to  remove  and  would  interfere  with 
the  uniting. 

The  roots  of  the  stock  should  be  cut  back  to  stubs  not  more  than 
one  inch  in  length.  If  left  longer  they  make  the  handling  of  the 
grafts  very  troublesome  and  are  of  little,  if  any,  use. 

Callusing.— When  the  grafts  are  made,  the  cuttings  are  completely 
dormant,  but  as  soon  as  they  are  placed  in  the  proper  favorable  con- 
ditions certain  of  their  tissues  become  active  and  the  changes  and  vital 
processes  commence  which  bring  about  the  rooting  of  the  stock,  the 
sprouting  of  the  scion,  and  the  uniting  of  one  to  the  other. 


FIG.  11.    Callusing  bed. 

These  favorable  conditions  do  not  usually  exist  in  the  nursery  at 
the  time  of  grafting,  so  that  if  the  grafts  are  planted  out  directly 
many  of  them  will  dry  out  or  be  injured  by  cold  and  moisture  before 
they  can  commence  active  growth.  For  this  reason  it  is  always  best, 
except  at  the  extreme  end  of  the  grafting  season,  to  "stratify"  the 
grafts  in  a  " Callusing"  bed,  where  the  conditions  of  moisture,  tem- 
perature, and  aeration  can  be  controlled. 

This  callusing  bed  is  usually  a  pile  of  clean  sand  placed  on  the  south 
side  of  a  wall  or  building  and  surrounded  by  a  board  partition  where 
there  is  no  possibility  of  its  becoming  too  wet  by  the  flow  of  water 
from  a  higher  level  or  from  an  overhanging  roof.  It  should  be  pro- 
tected, if  necessary,  by  a  surrounding  ditch.  It  should  be  furnished 
with  a  removable  cover  of  canvas  or  boards  to  protect  it  from  rain  and 
to  enable  the  temperature  to  be  controlled  by  the  admission  or  exclusion 
of  the  sun's  rays.  A  water-proof  wagon-cover,  black  on  one  side  and 
white  on  the  other,  is  excellent  for  this  purpose. 


114 


UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 


The  bottom  of  the  callusing  bed  is  first  covered  with  2  or  3  inches 
of  sand.  The  bundles  of  grafts  are  then  placed  in  a  row  along  one  end 
of  the  bed,  and  sand  well  filled  in  around  them.  The  bundles  should  be 


FIG.  12.    Plan  of  Callusing  bed. 


placed  in  a  slightly  inclined  position  with  the  scions  uppermost,  and 
the  sand  should  be  dry  enough  so  that  it  sifts  in  between  the  grafts  in 
the  bundle.  The  bundles  of  grafts  are  then  covered  up  completely 
with  sand,  leaving  it  at  least  2  inches  deep  above  the  top  of  the  scion. 


FIG.  13.    Wire  graft  properly  callused. 

Another  row  is  then  placed  in  the  same  manner  until  the  bed  is  full. 
Finally  a  layer  of  2  or  3  inches  of  moss  or  straw  is  placed  over  all. 
(See  Figs.  11  and  12.) 

The  callusing  bed  may  be  made  much  deeper  and  the  bundles  of 
grafts  laid  horizontally  in  superposed  layers.     This  method  economizes 


FIG.  14.    Effect  of  different  amounts  of  moisture  on  the  production 

of  callus,  roots  and  shoots. 

A.  Cuttings  callused  in  sand  containing  15  per  cent  of  moisture.  B.  Cuttings  callused 
in  sand  containing  10  per  cent  of  moisture.  C.  Cuttings  callused  in  sand  containing  5  per 
cent  of  moisture.  D.  Cuttings  callused  in  sand  containing  2J  per  cent  of  moisture. 


116 


UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 


room,  but  makes  it  difficult  to  maintain  the  temperature  and  moisture 
conditions  regular  and  uniform  in  all  parts  of  the  bed. 

In  the  callusing  bed  we  should  endeavor  to  hasten  and  perfect  the 
union  of  stock  and  scion  as  much  as  possible  while  delaying  the  start- 
ing of  the  buds  and  the  emission  of  the  roots.  The  latter  processes 
require  more  moisture  than  the  formation  of  healing  tissue,  therefore 
the  sand  should  be  kept  comparatively  dry.  Between  5  and  10  per  cent 
of  water  in  the  sand  is  sufficient.  The  purer  the  sand  the  less  water  is 


FIG.  15.    Showing  the  independence  of  root 
and  callus  formation. 

necessary.  There  should  be  a  little  more  moisture  present  than  in  the 
sand  used  for  keeping  the  cuttings  over  winter.  Too  much  moisture 
will  stimulate  the  emission  of  roots  and  starting  of  buds  without  aiding 
the  callus  formation,  as  is  well  shown  in  Fig.  14. 

The  formation  of  callus,  or  healing  tissue,  is  a  perfectly  distinct 
process  from  the  formation  of  roots.  The  independence  of  these  pro- 
cesses is  shown  in  Fig.  15,  where  an  abundant  growth  of  callus  is 
shown  on  the  cut  surface,  while  roots  are  shown  growing  only  above 
the  cut  surface. 


RESISTANT    VINEYARDS— GRAFTING,    PLANTING,    CULTIVATION.         117 

All  the  vital  processes  progress  more  rapidly  when  the  cuttings  are 
kept  warm.  To  delay  them,  therefore,  we  keep  the  sand  cool,  and  to 
hasten  them  we  make  it  warm.  In  the  beginning  of  the  season  and 
up  to  the  middle  of  March  we  keep  the  sand  cool.  This  is  done  by 
keeping  the  bed  covered  during  the  day  when  the  sun  is  shining,  and 
uncovering  occasionally  at  night  when  there  is  no  fear  of  rain.  If  the 
black-and-white  wagon-cover  is  used  the  white  side  should  be  placed 
outward  to  reflect  the  heat.  The  temperature  should  be  kept  about 
60°  F.  or  lower. 

About  the  middle  of  March  the  temperature  of  the  bed  should  be 
raised.  This  is  done  by  removing  the  cover  during  warm  days  and 
carefully  covering  at  night.  If  necessary  the  layer  of  moss  or  straw 
should  be  removed  on  sunny  days  and  then  replaced.  The  temperature 


68°  F.  77°  F.  86°  F. 

FIG.  16.    Callus  formed  at  various  temperatures  in  eight  days. 

of  the  sand  at  the  level  of  the  unions  should  be  about  75°  F.  during 
this  period.  If  the  temperature  rises  higher  than  this  there  will  be  a 
more  abundant  production  of  callus,  but  it  will  be  soft,  easily  injured, 
and  liable  to  decay. 

At  the  end  of  four  weeks  after  warming  the  bed,  the  union  should  be 
well  cemented.  The  callus  should  not  only  have  formed  copiously 
around  the  whole  circumference  of  the  wound,  but  it  should  have 
acquired  a  certain  amount  of  toughness  due  to  the  formation  of  fibrous 
tissue.  It  should  require  a  pull  of  several  pounds  to  break  the  callus 
and  separate  stock  and  scion.  When  the  callus  has  acquired  this  quality 
the  grafts  are  in  condition  to  be  planted  in  the  nursery,  and  may  be 
handled  without  danger.  If  taken  from  the  bed  while  the  callus  is 
still  soft,  many  unions  will  be  injured  and  the  grafts  will  fail,  or  unite 
only  on  one  side. 

If  left  as  long  as  this  in  the  callus  ing  bed  most  of  the  scion  buds 
will  have  started  and  formed  white  shoots.  These  shoots,  however, 

3— BUL.  180. 


118  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

should  not  be  more  than  ~y.2  to  1  inch  long.  If  they  are  longer  the  bed 
has  been  kept  too  wet  or  too  warm.  Roots  will  also  have  started 
from  the  stock,  but  these  also  should  not  be  over  i/>  inch  long.  The 
grafts  should  be  handled  as  carefully  as  is  practicable,  but  there  is 
no  objection  to  breaking  off  any  scion  shoots  or  stock  roots  which 
have  grown  too  long.  It  is  almost  impossible  to  save  them,  and  new 
ones  will  start  after  the  grafts  are  planted,  and  make  a  "perfectly 
satisfactory  growth. 


FIG.  17.    Callused  whip  grafts.    (Callus  too  abundant.) 

Planting  in  the  Nursery.— The  grafts  are  planted  in  the  nursery  in 
rows  wide  enough  apart  to  allow  of  horse  cultivation,  and  wide 
enough  apart  in  the  rows  to  give  each  graft  room  to  develop.  The 
richer  the  soil  and  the  better  its  condition  the  more  grafts  may  be 
planted  to  the  acre.  The  more  space  each  graft  is  given  the  larger 
it  will  grow.  If  the  grafts  are  starved  either  by  poverty  of  the  soil 
or  being  planted  too  close  they  will  not  only  fail  to  grow  vigorously, 
but  the  unions  will  be  less  perfect  and  the  percentage  of  No.  1  grafts 
less. 

In  Europe  from  125,000  to  300,000  grafts  are  planted  to  the  acre. 
This  gives  each  plant  from  20  to  50  square  inches  of  surface.  In 
California  the  grafts  are  given  more  room.  The  rows  can  not  be 
placed  nearer  than  3  feet,  and  it  is  more  convenient  for  cultivation 
to  place  them  4  feet  apart.  In  most  soils  the  grafts  do  not  give  good 
results  if  placed  closer  in  the  rows  than  3  inches  apart.  In  a  rich. 


RESISTANT    VINEYARDS— GRAFTING,    PLANTING,    CULTIVATION.          119 


heavily  fertilized  soil  of  the  best  mechanical  texture  it  might  be 
possible  to  obtain  good  results  at  2  inches,  but  in  many  soils  it  is 
necessary  to  place  them  4  inches  to  get  good,  well-grown  plants. 

The  number  of  grafts  to  the  acre  and  the  space  given  to  each  is 
shown  in  the  following  table : 


Space  Between— 


Vines. 

2  inches 

2  inches 

3  inches 

3  inches 

4  inches 
4  inches 


Rows. 

36  inches 
48  inches 
36  inches 
48  inches 
36  inches 
48  inches 


Number  of  Grafts 
per  Acre. 


87,120 
65,340 
58,080 
43,560 
43,560 
32,670 


Number  of  Square  Inches 
per  Graft. 


72 
96 
108 
144 
144 
192 


The  grafts  may  be  planted  in  a  trench  made  with  a  spade.  It  is 
more  economical  and  better,  however,  if  the  soil  is  of  good  texture, 
properly  prepared  and  free  from  stones,  to  plant  them  with  a  dibble. 
Whichever  way  is  adopted  it  is  essential  that  the  greatest  regularity 
should  be  maintained  in  the  alignment  of  the  rows  and  in  the  depth 
of  the  planting. 

Before  planting  with  a  dibble  some  form  of  scraper  should  be  used 
which  will  make  a  shallow  ditch  from  12  to  18  inches  wide  and  about 
2  inches  deep,  perfectly  smooth  and  level  at  the  bottom.  A  line  is 
then  stretched  taut  about  1  inch  to  one  side  of  where  the  row  is  to 
be  and  2  inches  above  the  bottom  of  the  ditch.  The  grafts  are  then 
planted  with  the  dibble,  being  put  down  to  such  a  depth  that  the 
top  bud  comes  exactly  even  with  the  taut  line. 

Two  of  the  best  forms  of  nursery  dibbles  are  shown  in  Fig.  18.  The 
first,  a,  consists  of  a  piece  of  round  %-inch  iron,  IS  inches  long, 
furnished  with  a  wooden  handle  at  one  end  and  a  curved  double 
point  with  a  V-shaped  cleft  at  the  other.  The  bottom  node  of  the 
stock  is  caught  in  the  cleft  and  the  graft  forced  down  to  the  desired 
depth.  Unless  the  ground  is  very  light  the  other  form  of  dibble  is 
preferable. 

The  other  dibble,  b,  consists  of  a  sword-shaped  piece  of  iron  18 
to  20  inches  long  and  2  inches  wide,  furnished  also  with  a  handle. 
The  usual  way  of  using  it  is  to  press  it  into  the  ground  to  the  desired 
depth,  open  the  hole  a  little  with  a  lateral  thrust,  withdraw  it  and 
insert  the  graft.  The  dibble  is  then  pushed  into  the  ground  again 
at  about  an  inch  to  one  side  of  the  graft  and  by  another  lateral 
thrust  the  earth  is  pressed  tightly  around  the  graft.  This  takes 
more  time  than  is  necessary  with  the  other  form  of  dibble,  and  unless 
done  carefully  there  is  danger  of  failing  to  make  the  soil  close  around 


120 


UNIVERSITY  OF   CALIFORNIA — EXPERIMENT   STATION. 


the  base  of  the  stock,  which  is  thus  left  surrounded  by  an  air  space. 
Grafts  left  in  this  way  are  apt  to  become  moldy  and  fail  to  make 
good  roots. 

Both  these  objections  are  overcome  by  using  the  dibble  as  shown 
in  Fig.  19.  When  used  in  this  way  the  dibble  is  pushed  into  the 
ground  only  once  for  each  graft  and  there  is  no  possibility  of  the 


j 


a 


FIG.  18.     Dibbles  for  planting  grafts. 

graft  being  suspended  without  soil  in  contact  with  the  base.  Two 
men  work  together,  one  placing  the  grafts  and  the  other  manipulating 
the  dibble. 

Where  it  is  necessary  to  plant  in  compact  soil  or  in  soil  containing 
pebbles  a  dibble  can  not  be  used.  In  this  case  it  is  necessary  to  dig 
a  trench.  The  trench  should  be  dug  with  one  side  slightly  slanting. 
The  grafts  are  laid  against  this  side  and  well-pulverized  soil  shoveled 
in.  If  the  soil  is  at  all  stiff  or  clayey  a  couple  of  inches  of  sand  should 


RESISTANT    VINEYARDS— GRAFTING,    PLANTING,    CULTIVATION.         121 

be  placed  on  the  side  of  the  bottom  of  the  trench  where  the  bottom 
of  the  stock  rests.  This  will  very  much  facilitate  the  rooting.  (See 
Fig.  20.) 

When  the  grafts  are  planted  they  should  be  completely  covered, 
and  very  carefully,  with  1  or  2  inches  of  soil.     This  will  leave  the 


\D' 


I 


1 


FIG.  19.    ILLUSTRATING  METHOD  OF  PLANTING  WITH  DIBBLE. 

D.    Position  of  dibble  when  pressing  the  soil  against  graft  7  and  opening  a  hole  for  graft  8. 
DI.    Position  of  dibble  when  preparing  to  press  soil  against  graft  8. 

S.    Loose  soil,  which  falls  to  bottom  of  hole  and  makes  it  possible  to  place  the  graft  at  exactly 
the  right  depth. 

nursery  in  ridges,  with  the  unions  of  the  grafts  in  the  center  of  the 
ridges  and  at  the  original  level  of  the  soil.  The  depressions  between 
the  ridges  will  be  about  2  inches  lower  than  the  unions.  This  is 
advisable,  as  it  makes  it  possible  to  irrigate  the  grafts  without  injur- 


FIG.  20.    Method  of  planting  grafts  in  trenches. 

ing  the  union  by  too  much  water.     The  ridges  should  be  wide.     If 
too  narrow  and  steep  they  dry  out  too  easily  and  the  unions  will  suffer. 

Cultivation.— By  the  end  of  April  all  the  grafts  should  be  planted 
and  a  good  irrigation  soon  after  this  is  advisable.  This  should  be 
done  in  such  a  way  that  the  ground  at  the  base  of  the  stock  will  be 
well  wetted.  This  will  start  the  formation  of  roots.  The  ridges 


322 


UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 


should  not  be  submerged,  but  they  should  be  wetted  sufficiently  to 
prevent  any  danger  of  the  drying  out  of  the  scions.  This  is  accom- 
plished by  lateral  seepage,  if  the  water  is  run  slowly  along  the  hollows 
between  the  ridges.  A  cultivator  should  be  run  between  the  rows 
as  soon  as  possible  after  the  irrigation,  but  the  ridges  should  not 
be  disturbed,  if  it  is  possible  to  avoid  it,  until  the  scions  start. 

If  the  soil  has  a  tendency  to  form  a  crust,  however,  it  will  be 
necessary  to  break  this  crust  after  any  rain  that  may  occur  at  this 
time.  This  is  one  of  the  most  fruitful  causes  of  failure.  If  the  crust 
is  not  broken  the  buds  will  have  difficulty  in  pushing  their  way 
through  and  the  hard  soil  will  dry  down  rapidly  and  many  scions 
be  killed.  The  breaking  of  the  crust  must  be  done  with  great  care, 


;*  «-:-  * 


f 


FIG.  21.     Irrigating  the  nursery. 

or  the  scions  will  be  disturbed  and  make  poor  unions.  If  2  inches 
of  soil  have  been  placed  over  the  scions  a  careful  man  can  go  over 
the  ridges  with  a  short-toothed  rake  without  injuring  any  grafts. 
This  should  be  done  as  soon  as  the  soil  is  dry  enough  not  to  form 
clods  and  before  a  crust  has  formed.  It  is  better  in  this  way  to 
prevent  the  formation  of  a  crust  than  to  break  it  up  after  it  has 
formed.  This  requires  very  prompt  and  rapid  action,  for  in  some 
soils  a  crust  forms  in  less  than  twenty-four  hours  after  a  rain. 

Until  about  the  first  or  middle  of  July  there  is  nothing  to  do  to 
the  nursery  but  to  keep  the  weeds  down,  and  to  see  that  the  scions 
do  not  become  dry  before  they  are  supplied  with  water  by  the  new 
roots. 

The  shoots  from  the  scions  should  begin  to  appear  above  the  ground 
in  one  to  two  weeks  after  planting.  These  shoots  are  at  first  yellowish 


RESISTANT    VINEYARDS  — GRAFTING,    PLANTING,    CULTIVATION.          123 

and  are  growing  at  the  expense  of  the  food  material  stored  up  in 
the  scion.     As  soon  as  roots  are  formed  the  shoots  become  a  deeper 


FIG.  22.    Effect  of  failure  to  remove^scion  roots. 

green  and  are  then  obtaining  food  from  the  roots  and  from  the  air. 
By  this  time  the  unions  are  well  formed,  and  the  scions  being  supplied 
with  water  by  their  own  roots  and  by  those  of  the  stock  are  in  less 


124  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

danger  of  drying  out.  The  sides  of  the  ridges  should  now  be  kept 
loose  by  hoeing,  and  the  ground  between  the  rows  pulverized  by 
frequent  cultivation. 

Removal  of  Scion  Roots.— As  soon  as  the  roots  on  the  stock  have 
started,  the  unions  should  be  examined  and  all  roots  which  have 
started  from  the  scions  should  be  removed.  This  will  be  about  the 
beginning  of  July  in  the  warmer  districts,  and  about  the  end  of  that 
month  in  the  cooler.  The  exact  time  is  determined  by  digging  up 
a  few  grafts  in  various  parts  of  the  nursery  and  examining  the  bases 
of  the  stocks.  If  all  have  formed  roots  it  is  time  to  take  off  the 
scion  roots. 

The  scion  roots  are  useful  to  the  graft  in  keeping  the  scion  alive 
and  perfecting  the  union  before  the  stock  roots  start,  and  they  should, 
therefore,  not  be  removed  too  soon.  The  roots  on  the  stock  start  later 
because  they  are  deeper  in  the  soil,  where  the  temperature  is  lower. 
If  the  scion  roots  are  allowed  to  grow  too  long,  however,  they  take 
the  nourishment  elaborated  by  the  scion  leaves  and  the  stock  roots 
are  starved.  (See  Fig.  22.)  In  this  way  we  may  get  a  large  growth  of 
leaves  on  the  scion  and  a  small  growth  of  roots  on  the  stock.  If  we 
remove  the  scion  roots  too  late,  therefore,  the  stock  roots  may  be 
insufficient  to  supply  the  large  growth  of  leaves  with  the  water  they 
need,  and  the  graft  will  die.  It  is  well,  whenever  particularly  large 
roots  are  cut  off  the  scion,  to  cut  back  the  shoot  and  to  remove  some 
of  the  leaves.  This  diminishes  evaporation  and  delays  the  growth  of 
the  scion  until  the  stock  has  developed  sufficient  roots  to  supply  it 
with  the  necessary  water. 

Removal  of  Raffia  and  Suckers.— At  the  same  time  that  the  scion 
roots  are  removed,  the  tying  material,  raffia  or  string,  should  be  cut 
on  all  the  grafts  where  it  has  not  rotted.  On  the  late  grafts  planted 
directly  in  the  nursery  without  previous  callusing  the  raffia  will  not 
require  cutting  if  it  has  been  used  without  bluestoning.  The  raffia 
or  other  tying  material  should  be  entirely  removed  or  the  grafts  will 
be  strangled.  (See  Fig.  23,  6.) 

If  the  stocks  have  been  properly  disbudded  before  grafting  they 
will  produce  very  few  suckers.  Those  which  do  grow  should  be 
removed  as  soon  as  they  show  above  the  ground,  and  any  that  are 
found  when  the  scion  roots  are  attended  to  should  be  carefully  cut 
off.  To  perform  these  various  operations  it  is  necessary  to  dig  down 
beside  the  grafts  to  below  the  union.  After  they  are  finished  the 
soil  should  be  replaced,  but  the  ridges  are  not  made  quite  so  high 
as  before.  The  unions  should  be  covered  up  and  any  shoots  which 
are  very  white  should  be  protected  by  drawing  the  soil  up  around 


RESISTANT    VINEYARDS  — GRAFTING,    PLANTING,    CULTIVATION.          125 

them.  This  lowering  of  the  ridges  is  useful  in  gradually  hardening 
the  unions.  The  soil  is  allowed 'to  become  dry  around  the  unions 
and  they  are  thus  prepared  for  the  complete  removal  of  the  soil 
around  the  unions  which  should  take  place  later  at  a  subsequent  hoeing. 

Digging  the  Grafts. —The  grafts  may  be  removed  from  the  nursery 
at  any  time  after  the  leaves  have  turned  yellow  and  before  they  are 
needed  for  planting  in  the  spring.  It  is  best,  however,  to  wait  until 
the  leaves  have  fallen  and  the  vines  are  perfectly  dormant.  If  dug 


a  b  c 

FIG.  23.    Effect  of  failure  to  remove  raffia. 

at  this  time  and  kept  in  a  cool  place  the  buds  will  not  start  as  soon 
as  if  they  are  left  in  the  ground. 

The  grafts  should  be  dug  carefully  in  order  not  to  injure  the  top, 
body,  or  union.  Cutting  the  roots  does  no  harm,  but  tearing  them 
off  should  be  avoided.  They  can  be  removed  satisfactorily  with  a 
nursery  plant-digger. 

Sorting  the  Grafts.— As  soon  as  the  grafts  are  out  of  the  ground  they 
should  be  carefully  sorted  into  three  lots  in  accordance  with  their 
root  and  top  growth,  and  especially  with  regard  to  the  strength  and 
completeness  of  the  union.  These  lots  are  called  No.  1  grafts,  No.  2 
grafts,  and  culls.  The  No.  1  grafts  are  those  suitable  for  planting 
in  the  vineyard ;  the  No.  2  grafts  may  be  replaced  in  the  nursery,  and 
the  culls  are  rejected  altogether. 


126  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

A  No.  1  graft  should  have  a  top  growth  of  well-ripened  wood  at 
least  10  inches  long  and  well-developed  roots  at  the  bottom  of  the 
stock.  It  should  have  no  large  scion  roots  or  scars  where  they  have 
been  removed.  It  should  not  show  injuries  due  to  digging,  and  there 
should  not  be  a  great  difference  of  diameter  between  the  stock  and 
scion.  The  most  important  point  is  the  condition  of  the  union.  The 
stock  and  scion  should  be  united  firmly  on  both  sides  and  the  union 
should  be  the  strongest  part  of  the  vine.  A  No.  1  graft  if  bent 
sufficiently  will  break  either  above  or  below,  but  not  at  the  union. 
(See  Fig.  24.) 

The  allowable  difference  in  size  between  stock  and  scion  will  differ 
according  to  the  varieties  grafted.  A  Rupestris  St.  George  or 
Mourvedre  X  Rupestris  1202  stock  should  be  as  large  as  the  scion; 
a  Riparia  X  Rupestris  3309  or  3306  may  be  from  one  fifth  to  one 
fourth  smaller,  while  a  Riparia  gloire  may  be  from  one  fourth  to 
one  third  smaller. 

The  lump  or  swelling  which  in  nearly  all  cases  occurs  just  above 
the  union  should  not  be  too  pronounced.  When  large  it  is  a  sign  of 
lack  of  affinity  between  stock  and  scion  or  of  an  imperfect  union. 
(See  Fig.  23,  a,  c.) 

The  No.  2  grafts  are  those  which  have  some  of  the  defects  mentioned 
above,  but  which  may  develop  into  good  vines.  As  there  is  doubt 
of  this,  however,  they  should  not  be  planted  directly  in  the  vineyard, 
but  placed  in  nursery  for  another  season.  The  following  year  a 
large  proportion  of  them  will  have  overcome  their  defects  and 
developed  into  good  two-year-old  vines.  Grafts  which  have  united 
well  on  one  side  or  which  have  complete  unions  but  small  growth 
may  be  saved  in  this  way,  .though  it  would  probably  be  better  for 
the  vineyard  to  plant  nothing  but  No.  1  one-year-old  grafts. 

Certain  defects  can  not  be  overcome.  Grafts  which  have  made  a 
heavy  top  growth  by  means  of  scion  roots  and  of  which  the  stock  is 
small  and  starved  should  be  thrown  away.  (See  Fig.  22.)  If  the 
union  is  imperfect  on  both  sides,  or  if  the  enlargement  above  the  union 
is  excessive,  there  is  no  hope  of  making  good  vines  of  them.  (See 
Fig.  23,  a,  c.) 

Pruning.— It  is  best  not  to  prune  the  grafts  until  they  are  planted 
or  afterwards.  If  the  tops  have  made  a  very  large  growth  with  large 
laterals  they  may  be  pruned  partially  in  order  to  facilitate  making 
up  into  bundles  and  shipping.  All  shoots  may  be  cut  off  except  the 
largest,  which  should  be  left  full  length  if  not  more  than  18  inches 
long.  When  the  grafts  are  tied  up  in  bundles  the  roots  may  be 
shortened  to  6  inches.  This  is  best  done  by  placing  the  bundles  on 
a  wooden  block  and  cutting  the  roots  with  a  sharp  broadax. 


\ 


FIG.  24.    No.  1  rooted  bench  grafts. 


128  UNIVERSITY  OF   CALIFORNIA — EXPERIMENT   STATION. 

Conservation  and  Shipping.— Rooted  vines  require  much  more  care 
than  cuttings,  as  they  are  more  easily  damaged.  They  are  especially 
liable  to  injury  by  drying-out.  Grafts  are  even  more  sensitive.  They 
should  be  kept  in  a  cool,  moist  place  until  they  are  shipped  or  planted. 
A  good  way  is  to  heel  them  in  under  an  open  shed  or  on  the  north 
side  of  a  building  in  sand  or  loam  where  there  is  no  danger  of  their 
getting  too  wet.  If  it  is  necessary  to  heel  them'  in  out  in  the  open 
field  they  should  be  protected  from  the  sun  by  placing  over  them  a 
bed  of  straw  at  least  2  feet  thick. 

Nursery  Grafting. — Certain  varieties  of  stocks,  such  as  Lenoir  and 
some  of  the  Berlandieri  and  ^Estivalis  hybrids  which  root  with 
difficulty,  do  not  give  good  results  with  cutting  grafting  and  must  be 
rooted  first,  as  already  described  on  page  112.  If  they  have  made  a 
good  stand  in  the  nursery  and  there  are  not  too  many  vacant  spaces, 
they  may  be  grafted  without  removal.  This  is  known  as  "nursery 
grafting."  Cuttings  under  %  incn  in  diameter  of  other  varieties 
may  also  be  rooted  in  the  nursery  and  grafted  the  next  year  without 
removal. 

Either  the  tongue  graft  or  the  wire  graft  may  be  used.  If  the 
vines  have  made  a  large  growth  and  are  over  y2  incn  in  diameter  it  is 
better  to  use  one  of  the  methods  described  on  page  137.  (See  Fig.  26.) 

The  tongue  graft  is  difficult  to  make  in  the  nursery  and  the  tying 
is  particularly  troublesome.  Good  results  can  be  obtained  often  by 
omitting  the  tying,  but  the  scions  send  out  large  numbers  of  roots. 
The  wire  method  is  particularly  well  suited  to  nursery  grafting,  is 
very  easily  performed,  and  gives  excellent  results.  Over  90  per  cent 
of  first-class  unions  should  be  obtained. 

The  grafting  should  be  done  as  near  the  surface  of  the  ground  as 
possible.  The  soil  is  first  hoed  away  and  carefully  cleaned  off  the 
vines,  leaving  them  in  a  little  trench  3  or  4  inches  deep.  They  are 
then  cut  of?  with  pruning  shears  just  below  the  bud  of  the  original 
cutting  which  is  nearest  to  the  surface.  The  grafting  is  then  done 
in  the  same  way  as  already  described  for  cutting  grafts.  The  same 
care  in  cultivation,  removal  of  suckers,  scion  roots,  and  tying  material 
is  necessary. 

Grafts  made  in  this  way  are  very  large  and  vigorous  and  will  give 
good  results  if  handled  properly  in  the  vineyard.  There  are  the  same 
objections  to  them  as  to  any  very  large  plants,  however.  They  are 
more  liable  to  injury  than  smaller  plants  in  removal  from  the  nursery, 
require  more  care  in  planting,  and  are  more  liable  to  suffer  from 
the  difference  of  conditions  between  the  nursery  and  the  vineyard. 


RESISTANT    VINEYARDS— GRAFTING,    PLANTING,    CULTIVATION.         129 


II.    THE  VINEYARD. 

Preparation  of  the  Land. — Whatever  the  method  of  grafting  adopted, 
the  land  where  the  vineyard  is  to  be  planted  should  receive  the  same 
careful  preparation.  Profitable  vineyards  have  been  established  in 
some  soils  which  have  received  no  more  preparation  than  is  needed 
for  a  crop  of  wheat.  Such  cases  are,  however,  exceptional,  and  even 
in  these  cases  better  and  quicker  results  would  have  been  obtained 
if  the  ground  had  been  properly  prepared  before  planting.  The  need 
of  thorough  preparation  of  the  soil  is  more  urgent  when  we  plant 
resistant  vines  than  when  we  plant  vinifera  varieties  on  their  own 
roots.  This  is  owing  both  to  the  greater  sensitiveness  of  resistant 
roots  to  unfavorable  conditions  and  to  the  greater  cost  of  starting  a 
resistant  vineyard,  which  makes  the  necessity  of  quick  returns  more 
pressing. 

In  South  Africa  it  is  usual  to  obtain  a  crop  eighteen  months  after 
planting  bench  grafts.  This  crop  may  amount  to  five  tons  per  acre, 
and  even  more.  This  precocity  is  due  in  great  part  to  the  fact  that 
before  planting,  the  soil  of  the  vineyard  is  hand-trenched  to  a  depth 
of  30  inches  or  more.  Hand-trenching  is,  of  course,  out  of  the  question 
in  California,  where  labor  is  expensive.  We  can,  however,  approxi- 
mate these  results  by  deep  plowing  and  subsoiling.  Wherever  resist- 
ant vines  are  planted,  'the  soil  should  be  plowed  2  or  3  inches  deeper 
than  the  depth  to  which  the  bottom  of  the  cutting  or  graft  will  reach 
when  planted,  and  subsoiled  several  inches  below  this.  A  plow  which 
will  turn  the  soil  over  to  a  depth  of  12  inches,  followed  by  a  subsoiler 
stirring  the  soil  6  inches  deeper,  will  give  results  during  the  first 
three  years  of  the  life  of  the  vineyard  that  will  more  than  repay  the 
cost  in  crop  alone,  and  the  perfect  stand  and  strong  healthy  vines 
will  insure  good  crops  in  later  years.  It  is  doubtful  whether  a  vine 
which  is  starved  and  dwarfed  during  the  first  three  or  four  years 
of  its  life  ever  gives  the  best  results  in  crop. 

If  the  land  is  plowed  in  the  way  described  the  roots  of  the  graft 
when  planted  will  be  in  contact  with  top  soil,  which  is  the  best  for 
root  growth,  and  the  graft  should  make  a  growth  of  several  canes 
3  or  4  feet  long  and  a  strong  root  system  the  first  year. 

Fertilization. — As  a  rule,  no  general  fertilization  of  the  soil  is  needed 
the  first  year,  the  deep  plowing  being  sufficient  to  insure  a  strong 
growth.  When  replanting  the  site  of  an  old  vineyard  or  planting 
vines  on  land  which  has  been  occupied  by  an  orchard,  some  fertilizer 
to  renew  the  humus  of  the  soil  is  advisable.  A  crop  of  rye  or  peas 
plowed-in  the  year  previous  to  planting  is  useful  for  this  purpose. 
A  heavy  manuring  with  from  15  to  20  tons  of  well-rotted  stable 


130  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

manure  is  also  excellent,  when  it  can  be  procured.  The  manure  should 
be  spread  on  the  surface  and  plowed  in.  If  the  manure  is  not  well 
rotted,  however,  it  may  do  more  harm  than  good,  unless  applied  at 
least  twelve  months  before  the  planting.  The  vines  are  apt  to  dry  out 
or  become  moldy  at  the  base  if  they  are  in  contact  with  very  strawy 
manure. 

In  every  case,  it  is  advisable  to  place  a  little  nitrogenous  fertilizer 
below  each  vine  when  it  is  planted.  For  this  purpose  ground  or 
steamed  bones,  tankage,  or  old  stable  manure  may  be  used  with 
advantage.  Two  or  three  ounces  of  the  first  two  or  half  a  shovel  of 
the  last  well  dug  in  and  mixed  with  the  soil  at  the  bottom  of  each 
planting  hole  is  sufficient.  A  general  fertilization  of  the  land  is 
usually  best  postponed  until  the  second  year. 

Intercalary  Crops.— As  a  rule  it  is  better  not  to  try  to  raise  any 
crop  between  the  vines  unless  there  is  an  abundance  of  water.  In 
most  parts  of  California  the  young  vines  need  all  the  moisture  avail- 
able in  the  soil  during  summer  and,  unless  summer  irrigation  can  be 
given,  the  soil  between  the  vines  should  be  kept  clear  of  crops  and 
weeds.  With  irrigation  it  is  possible  to  raise  a  crop  of  corn  or  other 
hoed  crops  without  injury  to  the  vines  during  the  first  year,  providing 
nothing  is  grown  nearer  than  3  feet  from  the  vines.  After  the  first 
year  the  land  should  be  given  exclusively  to  the  vines. 

Planting. — If  the  ground  has  been  plowed  deeply,  as  already 
explained,  and  no  fertilizer  is  to  be  used,  the  grafts  may  be  planted 
with  a  dibble.  This  method  has  several  advantages  and  can  be  used 
in  all  soils  which  do  not  contain  large  stones  or  coarse  gravel.  It  is 
not  recommended,  however,  except  for  sandy  and  sandy-loam  soils. 
It  is  rapid  and  facilitates  the  perfect  alignment  of  the  vines,  as  well 
as  makes  it  much  easier  to  attain  the  very  important  object  of  placing 
the  unions  at  exactly  the  right  height  above  the  surface  of  the  ground. 
For  planting  in  this  way  the  roots  must  be  pruned  very  short.  The 
stronger  roots  must  be  pruned  down  to  y±  inch,  and  the  smaller 
removed  altogether.  There  is  probably  some  loss  of  strength  to  the 
vines  by  this  close  root  pruning,  but  it  is  not  very  serious.  The  young 
rootlets  start  from  the  cut  end  of  the  root  wherever  it  is  cut,  and  the 
main  advantage  of  a  rooted  vine  over  a  cutting  is  the  rapidity  with 
which  the  rootlets  start  and  grow.  However  long  we  leave  the  roots 
they  are  of  no  use  to  the  vine  until  they  have  developed  new  rootlets. 
If  we  leave  the  roots  longer  when  planting  with  a  dibble  they  will  be 
turned  up  when  planted,  which  will  result  in  crooked  and  improperly 
placed  roots. 

Fig.  18c  shows  a  convenient  form  of  dibble.    It  consists  of  a  sword- 


RESISTANT    VINEYARDS  — GRAFTING,    PLANTING,    CULTIVATION.          131 

shaped  piece  of  iron  about  15  inches  long,  a  handle  furnished  with  a 
cross-piece,  and  a  foot-rest.  In  use,  it  is  pressed  into  the  ground  by 
placing  the  foot  on  the  foot-rest  and  then  by  a  backward  and  forward 
movement  of  the  handle  the  hole  is  opened  in  the  soil  and  the  dibble 
removed.  This  hole  is  made  from  8  to  10  inches  deep,  according  to 
the  length  of  the  graft.  The  graft  is  then  inserted  to  the  right  depth 
and  the  dibble  pressed  into  the  ground  again  about  3  or  4  inches  from 
the  graft  and  a  few  inches  deeper  than  the  first  time.  Then  by  a 
vigorous  thrust  of  the  handle  the  blade  of  the  dibble  is  caused  to 
press  the  soil  tightly  around  the  graft.  An  ordinary  garden  spade 


FIG.  25.    Illustrating  method  of  planting  grafts.    (Redrawn  after  Hit-liter.) 

may  be  used  for  the  same  purpose.     It  is  particularly  necessary  that 
the  soil  should  be  in  intimate  contact  with  the  bottom  of  the  graft. 

Whatever  the  length  of  the  graft,  the  union  should  be  1  or  2  inches 
above  the  general  level  of  the  ground.  On  steep  hillsides  the  union 
should  be  placed  higher  —  4  inches  or  more  above  the  surface.  Unless 
this  is  done  the  union  will  soon  be  covered  by  the  soil  thrown  down 
by  the  sidehill  plows,  and  it  will  be  difficult  or  impossible  to  prevent 
the  growth  of  scion  roots.  Grafted  vines  for  use  on  hillsides  should 
be  from  2  to  4  inches  longer  than  for  level  soils.  The  stocks  should 
not  be  less  than  12  inches  long.  A  14-  or  15-inch  stock  and  a  one-bud 
scion  is  the  best  for  this  purpose.  As  soon  as  possible  after  planting, 
not  later  than  the  next  day,  the  soil  should  be  hoed  up  around  the 
graft,  leaving  a  broad  hill  reaching  at  least  2  or  3  inches  above  the 
union. 


132  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

If  the  soil  is  stony  or  imperfectly  prepared,  or  if  we  desire  to  apply 
fertilizers,  planting  with  a  dibble  is  impossible.  In  this  case  we  must 
dig  a  hole  for  each  vine.  This  hole  need  not  be  any  wider  than  the 
spade,  but  should  be  at  least  4  inches  deeper  than  the  bottom  of  the 
graft. 

The  method  of  planting  is  shown  in  Fig.  25.  As  soon  as  the  hole  is 
dug,  3  or  4  inches  of  top  soil,  mixed  with  fertilizer  if  it  is  used,  is  placed 
at  the  bottom.  The  vine  is  then  put  in  a  slanting  position  so  that  its 
base  is  near  the  middle  of  the  hole  and  its  top  against  the  marker. 
More  top  soil  is  then  thrown  in  until  the  hole  is  about  half  full.  The 
soil  is  then  pressed  with  the  foot  firmly  around  the  roots  and  bottom 
half  of  the  stock.  The  hole  is  then  filled  with  loose  soil  and  the  graft 
well  hilled  up  several  inches  above  the  union.  The  hill  should  be  very 
broad,  in  order  to  prevent  drying  out. 

With  this  method  of  planting  great  care  is  necessary  to  avoid  getting 
any  of  the  unions  too  deep.  If  the  unions  are  placed  below  the  surface 
of  the  soil  the  scion  will  send  out  roots.  If  these  roots  are  not  removed 
they  will  grow  large  and  finally  take  all  the  nourishment  coming  from 
the  leaves.  This  will  result  in  the  starvation  and  death  of  the  resistant 
root,  and  in  a  few  years  the  vine  has  nothing  but  vinifera  roots  and  is 
as  susceptible  to  injury  from  phylloxera  as  if  it  had  never  been  grafted. 
If  the  scion  roots  are  removed  twice  a  year  for  the  first  two  years 
and  once  a  year  until  the  vines  are  seven  or  eight  years  old  this 
result  may  be  avoided,  and  if  the  work  is  done  promptly  and  thoroughly 
few  scion  roots  will  be  formed  after  this.  To  do  this  properly,  how- 
ever, requires  a  great  deal  of  careful,  conscientious  work,  which  it  is 
difficult  to  have  done  on  a  large  scale,  and  which  may  be  avoided  by 
planting  the  grafts  at  the  right  depth. 

If  the  unions  are  placed  too  high  the  roots  are  brought  too  near  the 
surface  and  they  may  dry  out  before  they  have  time  to  grow  down  into 
the  permanently  moist  soil.  As  the  unions  should  be  well  covered 
with  soil  to  protect  them  from  the  sun  during  the  first  summer,  it  is 
necessary  to  make  very  large  mounds  if  the  unions  are  placed  very 
high. 

In  general  it  is  found  that  the  most  convenient  position  for  the  union 
is  about  2  inches  above  the  surface  of  the  ground.  This  will  bring  the 
bottom  of  the  graft  8  inches  below  the  surface  with  an  ordinary  10-inch 
stock.  This  is  sufficiently  deep  for  all  except  very  dry  and  open  soils, 
if  the  grafts  are  well  hilled  up  after  planting. 

In  planting  with  a  dibble  the  planter  can  estimate  the  height  of  the 
union  with  sufficient  exactness  by  eye,  but  when  planting  in  a  hole, 
especially  if  the  surface  of  the  ground  is  rough  or  uneven,  some  kind 
of  guide  is  necessary.  For  this  purpose  a  stick  3  feet  long  and  1  inch 
in  diameter  may  be  used.  This  stick  is  laid  across  the  hole,  and  shows 


RESISTANT    VINEYARDS  — GRAFTING,    PLANTING,    CULTIVATION.          133 

the  true  level  of  the  ground  and  serves  as  a  guide  to  show  the  planter 
where  to  place  the  union.  In  planting  with  a  number  of  men  where 
a  marked  rope  or  wire  is  used  to  show  the  position  of  each  vine  while 
planting,  this  rope  or  wire  may  be  used  as  the  guide  to  show  the  height 
€f  the  union,  provided  one  man  is  employed  in  watching  the  rope  to 
see  that  it  remains  stretched  at  exactly  the  right  height  above  the 
surface. 

Pruning. — The  pruning  of  the  roots  before  planting  has  already  been 
discussed.  The  top  is  usually  pruned  by  removing  all  the  shoots  except 
the  strongest  and  cutting  that  back  to  two  good  buds.  The  superfluous 
shoots  should  be  cut  off  clean  close  enough  to  the  base  to  remove  the 
base  bud.  The  shoot  which  is  left  should  be  cut  through  the  bud  above 
the  top  one  which  is  left. 

In  France  it  is  considered  better  to  postpone  the  cutting  back  of 
the  main  shoot  until  the  buds  have  started  after  planting,  as  indicated 
in  Fig.  25.  This  prevents  to  some  extent  the  early  starting  of  the 
bottom  buds  and  the  danger  of  their  injury  by  spring  frosts.  It  also 
protects  the  union  from  injury  during  the  period  which  elapses  between 
the  planting  and  the  commencement  of  growth. 

Staking.— To  obtain  the  best  results,  a  vineyard  of  bench  grafts 
should  be  staked  the  year  it  is  planted.  Bench  grafts  grow  more  rapidly 
than  ungrafted  vines.  This  is  especially  true  when  deep  preparation  of 
the  soil  has  been  practised.  Moreover,  with  most  varieties  the  scion  will 
be  a  little  larger  than  the  stock,  which  makes  the  vine  top  heavy  and 
more  likely  to  bend  over  and  lie  flat  on  the  ground.  To  prevent  this 
and  to  have  a  well-shaped  vine  from  the  beginning,  the  shoots  growing 
during  the  first  season  should  be  tied  up  to  a  stake.  If  this  is  done, 
it  will  be  possible  to  give  each  vine  a  straight,  smooth  stem  and  sym- 
metrical head  at  the  second  pruning.  It  is  only  in  this  way  that  the 
full  benefit  can  be  obtained  of  the  vigorous  growth  which  properly 
planted  grafts  make  during  the  first  two  years.  If  the  vines  are  allowed 
to  lie  on  the  ground  it  will  take  three  or  four  years  to  give  them  the 
proper  shape,  and  much  crop  is  lost  by  the  heavy  pruning  necessary 
for  this  purpose. 

The  size  of  stake  will  depend  on  the  style  of  pruning  that  is  to  be 
adopted  and  the  height  at  which  the  vines  are  to  be  headed.  For 
ordinary  short-pruned  vines  a  stake  3  feet  long  and  1  or  1^  inches  in 
diameter  is  quite  sufficient.  Such  a  stake  can  be  driven  2  feet  into 
the  ground  and  will  support  the  vine  perfectly  for  five  or  six  years  if 
the  head  is  made  at  the  usual  height  of  about  10  inches,  or  lower.  After 
this,  the  vine  should  be  stout  enough  to  stand  without  a  stake.  If  the 
4— BUL.  180. 


134  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

vines  are  to  be  pruned  long  or  given  a  high  head  a  4-  to  6-foot  stake 
will  be  needed  and  may  be  put  in  the  first  year.  As  all  vines  should  be 
pruned  short  for  the  first  three  years,  however,  it  is  as  well  to  use  small 
stakes  at  first  and  to  replace  them  with  longer  and  heavier  stakes  when 
long  pruning  is  commenced.  If  the  vines  are  to  be  headed  high,  15  to 
18  inches,  a  4-foot  stake  will  be  necessary,  and  this  will  have  to  be 
a  little  heavier,  1^  to  1%  inches  in  diameter. 

Suckering  and  Rooting.— If  No.  1  bench  grafts  from  which  the  stock 
buds  were  properly  removed  before  grafting  are  used,  and  if  they  are 
planted  in  the  way  described,  there  will  be  very  few  suckers  from  the 
stock,  or  roots  from  the  scion,  produced.  Any  which  do  grow,  however, 
must  be  very  carefully  and  completely  removed.  The  more  thoroughly 
this  is  done  during  the  first  year  the  less  trouble  there  will  be  later,  and 
after  the  third  year  there  should  be  hardly  any  suckers  and  no  scion 
roots  produced  at  all. 

As  the  unions  are  kept  covered  during  the  first  year  a  few  scion 
roots  will  be  produced,  especially  in  rich  and  moist  soil.  These  should 
be  cut  off  once  during  the  season  about  midsummer,  at  about  the  time 
of  the  second  hoeing.  Any  which  develop  after  that  may  be  removed 
at  the  winter  pruning.  No  scion  roots  will  be  formed  in  subsequent 
years  if  the  unions  are  above  the  surface  and  kept  uncovered,  as  they 
should  be. 

Some  stocks  such  as  Rupestris,  and  especially  Rupestris  St.  George, 
are  very  prone  to  throw  out  suckers,  but  careful  work  during  the  first 
three  years  will  overcome  this  tendency.  To  do  this  the  suckers  should 
never  be  allowed  to  mature.  Three  or  four  times  during  the  first  year 
the  vineyard  should  be  gone  over  carefully  and  every  sucker  cut  off 
close  down  to  the  stock  at  the  place  where  it  starts. 

If  a  piece  of  the  base  of  the  sucker  is  left,  especially  if  the  sucker  has 
matured,  a  lump  will  form  on  the  stock,  from  which  there  will  be  an 
inveterate  tendency  for  suckers  to  form.  A  little  extra  work  during 
the  first  year  will  prevent  the  need  of  a  great  deal  of  work  in  subsequent 
years.  For  the  first  three  or  four  years  the  collar  of  the  vine  should  be 
cleaned  off  down  4  or  5  inches  below  the  surface  every  winter  or  spring 
by  plowing  and  hoeing  away  from  the  vine.  This  will  expose  any 
suckers  which  have  been  overlooked  during  the  summer.  All  such 
suckers  should  be  cut  out  very  close,  care  being  taken  to  remove  the 
slight  enlargement  at  the  base  of  each  from  which  new  suckers  would 
start  in  the  following  summer. 

Cultivation.  —  The  cultivation  of  a  grafted  vineyard  does  not  differ 
in  any  way  from  that  of  an  ordinary  vineyard  of  vinifera  varieties. 
Deep  plowing  and  thorough  summer  cultivation  are  equally  necessary 


RESISTANT    VINEYARDS  — GRAFTING,    PLANTING,    CULTIVATION.          135 

and,  owing  to  the  tendency  of  many  grafted  vines  to  heavy  bearing, 
fertilization  is  more  likely  to  be  needed.  As  a  rule,  the  same  methods 
of  pruning  are  applicable.  With  very  vigorous  stocks,  such  as  Rupestris 
St.  George,  it  may  be  necessary  to  prune  some  varieties  longer  to 
counteract  a  tendency  to  "go  to  wood."  With  most  stocks,  on  the 
other  hand,  the  fertility  of  the  vines  is  increased  and  shorter  pruning 
is  advisable.  In  any  case  the  amount  of  pruning  can  be  determined 
by  the  strength  of  the  vine  itself  as  with  ungrafted  vines. 

III.     FIELD  GRAFTING. 

It  is  possible  to  start  a  resistant  vineyard  by  planting  the  stocks 
directly  in  the  field  and  grafting  them  there  after  they  are  rooted 
instead  of  planting  bench  grafts.  This  was  formerly  the  commonest 
method  and  is  still  largely  practised  in  some  districts.  It  is,  however, 
in  all  cases  less  satisfactory  and  more  expensive  than  the  methods 
already  described.  In  some  cases — on  steep  hillsides,  in  very  stony  or 
stiff  soil  —  it  is  almost  impossible  to  make  a  satisfactor}^  vineyard  by 
field  grafting.  Good  results  are  sometimes  obtained  by  this  method 
in  fairly  level,  loose  soils,  but  the  results  are  so  much  at  the  mercy 
of  the  weather  that  even  with  the  best  work  it  is  only  by  chance  that 
good  paying  vineyards  are  established  in  this  way.  Even  when,  by  an 
extraordinary  combination  of  favorable  conditions,  a  field-grafted 
vineyard  is  successfully  established  the  cost  is  always  more  than  the 
cost  of  a  similar  vineyard  started  with  bench  grafts. 

As  field  grafting  is  still  practised  to  a  considerable  extent,  and  as 
many  vineyards  of  resistant  stocks  have  been  planted,  it  seems  necessary 
to  describe  the  method. 

Preparation  of  the  Soil.  —  Thorough  plowing  and  subsoiling  are  even 
more  necessarj^  when  planting  ungrafted  resistants  than  when  planting 
bench  grafts.  This  is  because  good  results  can  be  obtained  only  if  the 
resistants  are  grafted  young,  and  this  makes  it  essential  to  obtain  a  good 
growth  the  first  year.  If  the  stock  remains  in  the  ground  for  two,  three, 
or  more  years  before  grafting,  it  becomes  hard  and  refractory  to  graft- 
ing and  good  unions  can  not  be  obtained.  The  stocks  should  make 
sufficient  growth  the  first  year  to  allow  of  their  being  grafted  the  spring 
following  the  planting. 

Cuttings  or  Hoots.  —  It  is  better,  whenever  possible,  to  plant  good 
cuttings  than  roots.  This  is  because  when  they  are  grafted  the  follow- 
ing year  the  wood  where  the  union  is  made  is  a  year  younger  than  in 
the  case  of  roots  and  the  unions  are  correspondingly  more  perfect.  This 
is  especially  true  with  Rupestris  and  Riparia  stocks,  which  make 


136  UNIVERSITY  OP   CALIFORNIA — EXPERIMENT  STATION. 

unreliable  unions  when  old.  With  vinifera  hybrids,  such  as  Aramon 
X  Rupestris  No.  2  and  Mourvedre  X  Rupestris  1202,  the  age  of  the 
stock  is  not  so  important. 

The  cuttings  should  be  very  carefully  selected  and  only  firm,  healthy, 
well-ripened  wood  used.  They  should  be  sufficiently  long  to  allow  4 
inches  of  the  top  to  be  left  above  the  surface  of  the  ground.  This  is 
very  necessary  in  order  to  make  it  possible  to  graft  above  the  surface, 
for  the  graft  must  be  made  on  the  part  of  the  vine  corresponding  to 
the  original  cutting.  To  graft  in  the  new  wood  which  has  grown  after 
planting  makes  it  necessary  to  wait  two  or  three  years,  as  the  first  year's 
growth  is  usually  too  thin.  Vines  grafted  in  this  way,  moreover,  give 
very  much  more  trouble  by  their  inveterate  habit  of  throwing  out 
suckers.  For  these  reasons  small,  thin  cuttings  or  the  tips  of  canes 
should  not  be  planted  in  the  field.  Such  cuttings,  if  well  ripened,  may 
be  planted  in  the  nursery,  where  they  will  make  a  good  growth  the  first 
year,  and  where  they  may  be  nursery  grafted. 

The  cuttings  of  some  resistant  stocks,  such  as  Aramon  X  Rupestris 
No.  2,  root  with  difficulty,  and  if  planted  directly  in  the  field  would 
require  much  replanting.  With  these  varieties  it  is  better  to  plant 
roots.  With  all  varieties  it  is  better  to  plant  roots  in  soils  where  cuttings 
strike  with  difficulty.  An  incomplete  stand  the  first  year  is  difficult  to 
overcome,  and  increases  the  expense  by  spreading  the  work  of  planting, 
grafting,  and  regrafting  over  several  years.  At  every  stage  of  the 
process  of  starting  a  vineyard  by  field  grafting  some  vines  may  be  lost 
or  spoiled,  and  it  is  only  by  the  most  thorough  and  careful  work  that 
it  is  possible  to  avoid  the  ragged,  uneven  collection  of  crippled  mon- 
strosities that  too  often  passes  for  a  resistant  vineyard. 

Age  for  Grafting.— Whenever  possible  the  vines  should  be  grafted 
the  year  after  planting.  Some  stocks  may  make  too  small  a  growth  of 
top  and  root  to  make  a  strong  graft  the  first  year,  and  it  will  be  necessary 
to  leave  such  stocks  a  year  longer.  Any  stock  which  is  %  inch  thick 
and  has  made  a  fair  top  growth  should  be  grafted.  It  is  a  great  mistake 
to  wait  two  or  three  years  until  the  vines  are  %  or  1  inch  thick,  as  is 
done  by  many  grafters. 

Methods  of  Grafting.—  Wherever  possible  the  vines  should  be  grafted 
at  or  above  the  surface  of  the  ground.  In  many  cases,  however,  this 
will  be  impossible.  Some  cuttings  will  have  failed  to  start  the  top  buds 
and  it  will  be  necessary  to  go  below  the  surface  to  find  a  smooth,  suitable 
part  of  the  stock  where  grafting  is  possible. 

The  kind  of  graft  to  use  will  depend  on  the  size  of  the  stock.  For 
stocks  up  to  %  inch  in  diameter  the  methods  of  tongue  and  wire  grafting 
already  described  are  the  best.  For  larger  vines  up  to  %  inch  a 


RESISTANT    VINEYARDS— GRAFTING,    PLANTING,    CULTIVATION.         137 


modification  of  the  ordinary  tongue  graft  is  the  best.     Reference  to 
Fig.  26,  B,  BB,  will  show  how  it  is  modified.    If  the  tongue  graft  were 


FIG.  26.     Methods  of  field  grafting. 
A.    Whip  graft  for  stocks  £  to  §  of  an  inch  in  diameter. 

B,  BB.    Whip  graft  for  stocks  §  to  J  of  an  inch  in  diameter. 

C,  CC.    Whip  graft  for  stocks  over  f  of  an  inch  in  diameter. 

made  in  the  usual  way  with  stocks  of  this  size  it  would  be  necessary 
to  use  excessively  large  scions,  which  is  undesirable,  or  to  have  the  barks 
unite  only  on  one  side.  By  cutting  the  bevel  of  the  stock  only  part 


138  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT   STATION. 

way  through  the  vines,  as  shown  in  Fig.  26,  B,  it  is  possible  to  make  a 
smaller  scion  unite  on  both  sides.  For  still  larger  vines,  those  over 
%  inch  in  diameter,  the  best  graft  is  the  ordinary  cleft,  shown  in 

Fig.  26,  0,  CC. 

Tying  and  Waxing.— No  wax  or  clay  should  be  used  on  the  graft. 
Anything  which  completely  excludes  the  air  prevents  the  knitting  of 
the  tissues.  A  little  clay,  cloth,  or  a  leaf  may  be  placed  over  the  split 
in  the  stock  when  the  cleft  graft  is  used,  simply  to  keep  out  the  soil. 
Otherwise  there  is  nothing  more  suitable  or  more  favorable  to  the 
formation  of  a  good  union  that  can  be  put  around  the  graft  than  loose, 
moist  soil.  If  the  soil  is  clayey,  stiff  or  lumpy  it  is  necessary  to  surround 
the  union  with  loose  soil  or  sand  brought  from  outside  the  vineyard. 

It  will  usually  be  necessary  to  tie  the  grafts.  A  well-made  cleft 
graft  often  holds  the  scion  with  sufficient  force  to  prevent  its  displace- 
ment and  no  tying  is  necessary.  Wherever  there  is  any  danger  of  the 
graft  moving,  however,  it  should  be  tied.  There  is  nothing  better  for 
this  purpose  than  ordinary  raffia.  The  raffia  should  not  be  bluestoned, 
as  it  will  last  long  enough  without  and  will  be  sure  to  rot  in  a  few 
weeks  and  the  trouble  of  cutting  it  will  be  avoided.  Cotton  string  or 
anything  which  will  keep  the  graft  in  place  for  a  few  weeks  may  also 
be  used. 

As  soon  as  the  graft  is  made  and  tied,  a  stake  should  be  driven  and 
the  union  covered  with  a  little  earth.  The  hilling  up  of  the  graft  may 
be  left  for  a  few  hours,  except  in  very  hot,  dry  weather.  Finally,  the 
whole  graft  should  be  covered  with  a  broad  hill  of  loose  soil  2  inches 
above  the  top  of  the  scion. 

Season  for  Field  Grafting.  — Field  grafting  should  not  be  commenced 
as  a  rule,  except  in  the  hottest  and  driest  localities,  before  the  middle 
of  March.  Before  that  there  is  too  much  danger  that  heavy  rains  may 
keep  the  soil  soaked  for  several  weeks— a  condition  very  unfavorable 
to  the  formation  of  good  unions.  In  any  case  the  grafting  should  not 
be  done  while  the  soil  is  wet.  Grafting  may  continue  as  long  as  the 
cuttings  can  be  kept  dormant.  It  is  difficult  to  graft  successfully, 
however,  when  the  bark  of  the  stock  becomes  loose,  as  it  does  soon  after 
the  middle  of  April  in  most  localities. 

Treatment  the  First  Year.  — Field  grafts  require  practically  the  same 
treatment  as  bench  grafts  in  the  nursery,  except  that  there  is  little  or 
no  danger  of  their  drying  out,  if  they  are  properly  mounded  up.  There 
is  usually  sufficient  sap  in  the  stock  to  keep  them  moist. 

They  should  be  disturbed  as  little  as  possible  for  two  or  three  months 
after  grafting.  Some  time  in  July  it  is  necessary  to  remove  the  suckers 


RESISTANT    VINEYARDS  — GRAFTING,    PLANTING,    CULTIVATION.          139 

and  scion  roots.  If  the  suckers  grow  rapidly  and  abundantly  it  may 
be  necessary  to  remove  some  of  them  before  this.  They  should  not  be 
allowed  to  grow  large  enough  to  shade  the  graft  or  to  render  their 
removal  difficult  without  injury  to  the  scion.  It  is  best  not  to  touch 


FIG.  27.  Old  grafted  vine  on  which  the  scion 
roots  have  been  allowed  to  grow.  The  upper 
series  of  roots  are  all  vinifera,  only  the  lower 
series  resistant.  This  vine  was  killed  by  phyl- 
loxera. 

the  scion  roots  until  the  middle  or  end  of  July,  when  they  should  be 
removed  with  the  same  care  exercised  in  the  nursery. 

As  the  graft  grows  it  should  be  tied  up  to  the  stake,  otherwise  it  is 
liable  to  be  broken  off  or  loosened  at  the  union  by  the  wind  or  the 
cultivators. 

Regrafting. — Perhaps  the  most  troublesome  and  unsatisfactory 
feature  of  field  grafting  is  the  necessity  of  regrafting  a  large  number 
of  stocks.  Though  exceptionally  as  high  as  95  per  cent  of  the  grafts 
have  been  known  to  grow,  the  usual  number  will  be  between  50  and 
75  per  cent,  and  even  of  these  some  will  be  weak,  owing  to  incom- 


140  UNIVERSITY   OP   CALIFORNIA — EXPERIMENT   STATION. 

plete  unions.  It  is  usual  to  attempt  to  regraft  all  the  stocks  which 
fail  to  grow  the  first  time.  This  is  done  the  following  spring  at  the 
same  time  that  the  grafting  of  the  vines  which  were  too  small  the  first 
year  is  undertaken. 

The  regrafting  must  be  done  one  joint  further  down  than  the  first 
grafting,  as  the  wood  will  be  unhealthy,  if  not  dead,  where  grafted 
the  previous  year.  This  in  most  cases  will  bring  the  union  below 
the  surface,  with  all  the  attendant  troubles  of  scion  roots.  (See  Fig. 
27.)  Unless  the  suckers  have  been  allowed  to  grow  the  previous  year 


FIG.  28.    Herbaceous  graft. 

where  the  grafts  failed,  the  stocks  will  be  weak  and  will  not  make 
good  unions.  Regrafting  very  seldom  gives  a  strong  healthy  vine,, 
and  some  even  of  the  advocates  of  field  grafting  believe  it  is  best  to> 
dig  up  all  the  vines  which  fail  the  first  year  and  replace  them  with 
bench  grafts. 

Herbaceous  Grafting. — Vines  may  be  grafted  during  the  summer 
by  using  the  canes  or  buds  of  the  current  year's  growth.  Numerous, 
methods  have  been  described  for  doing  this,  but  none  of  them  have 
met  with  much  success  in  California.  A  few  growers,  however,  have- 
successfully  budded  and  grafted  Rupestris  St.  George  stocks  during 
the  growing  season,  and  their  methods  may  be  of  use  as  an  adjunct 
to  field  grafting  and  to  a  smaller  extent  to  bench  grafting. 


RESISTANT    VINEYARDS  — GRAFTING,    PLANTING,    CULTIVATION.         141 

Instead  of  regrafting  below  the  ground  the  second  year  a  stock 
which  has  failed,  a  couple  of  suckers  may  be  allowed  to  grow  during 
the  summer  of  the  year  the  grafting  is  done,  and  these  suckers  may 
be  green  grafted  above  ground  the  same  or  the  following  summer. 
When  done  successfully  the  unions  are  so  perfect  that  the  passage 
of  sap  from  stock  to  scion  is  sufficiently  free  not  to  force  the  strong 
growth  of  shoots  from  the  stock  which  occurs  when  we  regraft  on 
new  wood  in  the  usual  way  when  the  vine  is  dormant. 

Figs.  28  and  29  show  two  forms  of  herbaceous  grafting  which  have 
been  successfully  practised  in  California.  Fig.  29  is  simply  the- 


FIG.  29.    Herbaceous  bud. 

ordinary  T  bud  used  by  nurserymen  on  fruit  trees.  Fig.  28  is  a 
tongue  graft  similar  to  that  already  described,  but  made  with  great 
care  to  obtain  a  perfect  fit. 

For  successful  green  grafting  the  wood  of  both  stock  and  scion 
must  be  in  just  the  right  condition  of  maturity.  If  the  grafting  is 
done  too  early  the  tissues  are  too  soft  and  brittle,  dry  out  too  easily, 
and  few  of  the  grafts  grow.  If  done  too  late  the  buds  can  not  be 
inserted  properly  and  the  grafts  have  not  time  to  make  a  complete 
union. 

The  following  extracts  from  a  letter  kindly  written  by  Mr.  Thomas 
Casalegna,  of  San  Martin,  Santa  Clara  County,  gives  some  very  valuable 
hints  regarding  the  herbaceous  budding  and  grafting  of  vines : 

"1.  All  buds  put  in  from  July  15  to  August  15  start  the  same  yearr 


142  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

but  may  be  injured  by  fall  frosts.  Those  put  in  from  August  15  to 
September  15  remain  dormant  until  the  following  year,  unless  the  stock 
is  exceptionally  vigorous. 

"2.    Budding  is  most  successful  in  the  month  of  August. 

"3.  The  buds  should  be  taken  from  canes  which  have  reached  the 
stage  of  maturity  indicated  by  the  pith  turning  white  and  just  before 
the  bark  turns  yellow. 

"4.  The  buds  are  inserted  on  canes  of  the  current  year's  growth, 
unless  the  vines  are  exceptionally  vigorous. 

"5.  Green  grafting  is  most  successful  in  June,  provided  the  scions 
are  hard  enough.  The  pith  must  be  white.  Younger  scions  with  green 
pith  have  completely  failed  with  me.  In  a  strong- growing  vineyard 
grafting  may  be  done  in  July. 

"6.  The  leaves  are  taken  off  the  scions  when  they  are  cut.  If  they 
are  to  be  used  immediately  they  are  placed  in  water;  if  to  be  carried 
some  distance  they  are  placed  in  a  wet  sack. 

"7.  I  tie  the  buds  and  grafts  with  German  knitting  yarn. 

"8.  I  find  that  green  grafting  is  more  successful  than  budding,  if 
care  is  taken  to  get  suitable  scions  in  June. ' ' 

The  season  for  herbaceous  grafting  will,  of  course,  vary  according  to 
the  locality.  Hot  weather  immediately  following  the  work  is  fatal  to 
most  of  the  grafts.  Mr.  Casalegna  states  that  if  two  or  three  cool  days 
follow  the  insertion  of  the  buds  or  scions  he  obtains  an  almost  perfect 
stand.  The  use  of  an  elastic  tying  material  such  as  yarn,  as  recom- 
mended, seems  essential.  If  raffia  is  used  the  shrinkage  of  the  tissues 
which  follows  grafting  allows  the  graft  to  become  loose  and  to  dry  out. 

COMPARISON  OF  VARIOUS  METHODS  OF  STARTING  A  RESISTANT  VINEYARD. 

Bench  grafting  cuttings  is  unhesitatingly  recommended  for  the 
following  reasons : 

1.  Both  stock  and  scion  are  young  and  of  the  same  size.     The  unions 
are,  therefore,  strong  and  permanent. 

2.  The  grafting  is   done   under   conditions  favorable  to   rapid   and 
effective  work. 

3.  The  grafting  can  be  done  in  any  weather,  and  may  extend  over 
three  or  four  months.  Bench  grafting  may  be  done  on  rainy  days  when 
other  work  is  not  pressing  or  can  not  be  done. 

4.  The  work  is  more  easily  supervised.     One  man  who  thoroughly 
understands  all  details  of  the  grafting  can  oversee  the  work  of  several 
unskilled  workmen,  which  makes  it  possible  to  employ  cheaper  labor 
for  much  of  the  work. 

5.  The  cultural  conditions  are  more  easily  controlled.    There  is  much 
less  danger  of  inferior  results  due  to  excessively  wet  or  dry  weather 


RESISTANT    VINEYARDS  — GRAFTING,    PLANTING,    CULTIVATION.          143 

during  the  growing  season.  In  the  nursery  the  vines  can  be  cultivated, 
irrigated,  and  generally  attended  to  much  more  perfectly  than  in  the 
field. 

6.  A  rigid  .selection  of  vines  for  planting  can  be  made,  rendering 
it  possible  to  have  nothing  in  the  vineyard  but  strong  plants  and  perfect 
unions. 

7.  As  perfect  a  stand  can  be  obtained  in  the  vineyard  the  first  year 
in  any  soil  or  season  as  can  be  obtained  when  planting  the  ordinary  non- 
resistant  vines.     (See  figure  on  cover.) 

8.  The  union  of  every  vine  can  be  placed  exactly  where  we  want  it. 

9.  The  land  where  the  vineyard  is  to  be  planted  can  be  used  for  other 
crops  for  one  year  longer  than  when  field  grafting  is  adopted. 

10.  All  the  cultural  operations  during  the  first  year  are  much  less 
expensive,  as  they  are  spread  over  a  much  smaller  area  of  land.     Two 
acres  of  nursery  will  produce  enough  bench  grafts  to  plant  one  hundred 
acres  of  vineyard. 

In  short,  starting  a  resistant  vineyard  by  means  of  bench  grafts  is 
much  better  than  by  any  other  method  used  at  present,  because  it  is  the 
least  costly  and  gives  the  best  results.  This  is  true  whether  we  produce 
our  own  bench  grafts  or  whether  we  buy  them  at  the  present  market 
rate.  Growers  are  earnestly  cautioned,  however,  against  planting  any 
bench  grafts  but  the  first  choice.  Second  and  third  choice  are  little 
better  than  field  grafts,  and  many  have  been  offered  for  sale  lately 
which  are  sure  to  give  disappointment  in  the  vineyard.  There  are 
several  nurserymen  in  the  State  now  who  are  producing  No.  1  bench 
grafts  which  are  equal,  and  for  planting  here  perhaps  superior,  to  any 
produced  in  Europe. 

With  regard  to  nursery  grafting  and  bench  grafting  roots,  all  that 
can  be  said  in  their  favor  is  that  they  are  fairly  good  methods  when 
bench  grafting  cuttings  is  impracticable.  They  enable  us  to  produce 
rooted  grafts  with  stocks  which,  owing  to  the  difficulty  with  which  they 
root,  are  very  difficult  to  bench  graft  as  cuttings.  By  their  means  we 
are  enabled  to  utilize  resistant  cuttings  which  are  too  small  to  bench 
graft,  and  a  larger  percentage  of  well-grown  grafted  vines  is  obtained 
from  the  nursery. 

On  the  other  hand,  as  the  stock  is  at  least  two  years  old  when  grafted 
there  is  reason  to  fear  that  with  some  stocks  many  unions  will  fail  as 
the  vines  become  older.  The  vines  are  larger  when  they  are  taken 
from  the  nursery,  which  increases  the  cost  of  removal,  and  there  is 
little  i,f  any  gain  in  growth  over  bench  grafts  when  planted  in  the 
vineyard.  Finally,  the  method  requires  a  year  longer  and  is  in  every 
way  more  expensive. 

Of  field  grafting,  nothing  favorable  can  be  said  except  that  it  is  more 
generally  understood  and  the  expense  and  work  are  spread  over  several 


144  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

years  instead  of  being  principally  in  the  first.  Many  of  its  disad- 
vantages may  be  inferred  from  what  has  already  been  said  of  the 
advantages  of  bench  grafting.  The  principal  are  the  extreme  difficulty 
of  obtaining  a  perfect  stand,  the  trouble  with  scion  roots  and  stock 
suckers,  the  impossibility  of  detecting  imperfect  unions  until  the  vines 
die,  and  finally  the  greater  ultimate  cost. 


ACKNOWLEDGMENTS. 

In  the  preparation  of  this  bulletin  I  have  been  greatly  assisted  by 
many  grape-growers  and  nurserymen  who  have  kindly  allowed  me  to 
examine  their  methods,  notably  by  Messrs.  Frank  Swett  of  Martinez, 
W.  G.  Doidge  of  Lodi,  George  E.  Roeding  of  Fresno,  and  Thomas 
Casalegna  of  Evergreen. 


STATION  PUBLICATIONS  AVAILABLE  FOR  DISTRIBUTION. 


REPORTS. 

1896.  Report   of    the    Viticultural    Work    during    the   seasons    1887-93,    with    data 

regarding  the  Vintages  of  1894-95. 

1897.  Resistant   Vines,   their    Selection,   Adaptation,   and   Grafting.      Appendix    to 

Viticultural  Report  for  1896. 

1898.  Partial  Report  of  Work  of  Agricultural  Experiment  Station   for  the  years 

1895-96  and  1896-97. 
1900.     Report  of  the  Agricultural  Experiment  Station  for  the  year  1897-98. 

1902.  Report  of  the  Agricultural  Experiment  Station  for  1898-1901. 

1903.  Report  of  the  Agricultural  Experiment  Station  for  1901-1903. 

1904.  Twenty-second  Report  of  the  Agricultural  Experiment  Station  for  1903-1904. 

BULLETINS. 

Reprint.     Endurance  of  Drought  in  Soils  of  the  Arid  Region. 

No.  128.     Nature,  Value  and  Utilization  of  Alkali  Lands,  and  Tolerance  of  Alkali. 
(Revised  and  Reprint,  1905.) 

131.     The  Phylloxera  of  the  Vine. 

133.     Tolerance  of  Alkali  by  Various  Cultures. 

138.  Citrus  Fruit  Culture. 

139.  Orange  and  Lemon  Rot. 

140.  Lands  of  the  Colorado  Delta  in  Salton  Basin,  and  Supplement. 

141.  Deciduous  Fruits  at  Paso  Rohles. 

142.  Grasshoppers  in  California. 

143.  California  Peach-Tree  Borer. 

144.  The  Peach-Worm. 

145.  The  Red  Spider  of  Citrus  Trees. 

146.  New  Methods  of  Grafting  and  Budding  Vines. 

147.  Culture  Work  of  the  Substations. 

148.  Resistant  Vines  and  their  Hybrids. 

149.  California  Sugar  Industry. 

150.  The  Value  of  Oak  Leaves  for  Forage. 

151.  Arsenical  Insecticides. 

152.  Fumigation  Dosage. 

153.  Spraying  with  Distillates. 

154.  Sulfur  Sprays  for  Red  Spider. 

155.  Directions  for  Spraying  for  the  Codling-Moth. 

156.  Fowl  Cholera. 

158.  California  Olive  Oil;   its  Manufacture. 

159.  Contribution  to  the  Study  of  Fermentation. 

160.  The  Hop  Aphis. 

161.  Tuberculosis   in   Fowls.      (Reprint.) 

162.  Commercial  Fertilizers.      (Dec.   1,   1904.) 

163.  Pear  Scab. 

164.  Poultry  Feeding  and  Proprietary  Foods.      (Reprint.) 

165.  Asparagus  and  Asparagus  Rust  in  California. 

166.  Spraying  for  Scale  Insects. 

167.  Manufacture  of  Dry  Wines  in  Hot  Countries. 

168.  Observations  on  Some  Vine  Diseases  in  Sonoma  County. 

169.  Tolerance  of  the   Sugar  Beet  for  Alkali. 

170.  Studies  in  Grasshopper  Control. 

171.  Commercial  Fertilizers.     (June  30,  1905.) 

172.  Further  Experience  in  Asparagus  Rust  Control. 

173.  Commercial  Fertilizers.      (December,  1905.) 

174.  A  New  Wine-Cooling  Machine. 

175.  Tomato  Diseases   in  California. 

176.  Sugar  Beets  in  the  San  Joaquin  Valley. 

177.  A  New  Method  of  Making  Dry  Red  Wine. 

178.  Mosquito  Control. 

179.  Commercial  Fertilizers.     (June,  1906.) 

CIRCULARS. 
No    1.     Texas  Fever.  No.  16.     Notes  on   Seed-Wheat. 

2.  Blackleg.  17.     Why     Agriculture     Should     be 

3.  Hog  Cholera.  Taught  in  the  Public  Schools. 
4      Anthrax.                                                       18.     Caterpillars  on  Oaks. 

5.     Contagious  Abortion  in  Cows.          '        19.     Disinfection    of    Stables. 

7.     Remedies  for  Insects.  20.     Reading    Course    in    Irrigation. 

9.     Asparagus  Rust.  21.     The      Advancement      of     Agri- 

10.  Reading  Course  in  Economic  cultural  Education. 

Entomology.     (Revision.)  22.     Defecation   of   Must   for   White 

11.  Fumigation   Practice.  Wine. 

12.  Silk   Culture.  23.     Pure  Yeast  in  Wineries. 

13.  The  Culture  of  the  Sugar  Beet. 
15.     Recent  Problems  in   Agriculture. 

What  a  University  Farm  is  For. 


UNIVERSITY  OF  CALIFOBNIA  PUBLICATIONS. 

COLLEGE  OF  AGRICULTURE, 
AGRICULTURAL  EXPERIMENT  STATION 

BERKELEY,  CALIFORNIA. 


OR  POWDERY  MILDEW  OF  THE  VINE 


By  FREDERIC  T.  BIOLETTI 


EFFECT  OF  OIDIUM  ON  YOUNG  GROWTH. 


BULLETIN    NO.   186 

(February,  1907) 


BERKELEY 
THE  UNIVERSITY  PRESS 


BENJAMIN  IDE  WHEELER,  Ph.D.,  LL.D.,  President  of  the  University. 

EXPEEIMENT  STATION  STAFF. 

E.  J.  WICKSON,  M.A.,  Acting  Director  and  Horticulturist. 

E.  W.  HILGARD,  Ph.D.,  LL.D.,  Chemist. 

W.  A.  SETCHELL,  Ph.D.,  Botanist. 

ELWOOD  MEAD,  M.S.,  C.E.,  Irrigation  Engineer. 

C.  W.  WOODWORTH,  M.S.,  Entomologist. 

R.  H.  LOUGHRIDGE,  Ph.D.,  Agricultural  Geologist  and  Soil  Physicist.  (Soils  and 
Alkali.) 

M.  E.  JAFFA,  M.S.,  Nutrition  Expert,  in  charge  of  the  Poultry  Station. 

G.  W.  SHAW,  M.A.,  Ph.D.,  Agricultural  Technologist,  in  charge  of  Cereal  Stations. 

GEORGE  E.  COLBY,  M.S.,  Chemist.  (Fruits,  Waters,  Insecticides.)  (Absent  on 
leave.) 

RALPH  E.  SMITH,  B.S.,  Plant  Pathologist  and  Superintendent  of  Southern  Cali- 
fornia Pathological  Laboratory  and  Experiment  Stations. 

A.  R.  WARD,  B.S.A.,  D.V.M.,  Veterinarian  and  Bacteriologist. 

E.  W.  MAJOR,  B.Agr.,  Animal  Industry. 

F.  T.  BIOLETTI,  M.S.,  Viticulturist.     (Grapes,  WTine,  and  Zymology.) 
H.  M.  HALL,  M.S.,  Assistant  Botanist. 

H.  J.  QUAYLE,  A.B.,  Assistant  Entomologist. 

JOHN  S.  BURD,  B.S.,  Chemist  in  charge  of  Fertilizer  Control. 

C.  M.  HARING,  D.Y.M.,  Assistant  Veterinarian  and  Bacteriologist. 
E.  H.  SMITH,  M.S.,  Assistant  Plant  Pathologist. 

H.  J.  RAMSEY,  M.S.,  Assistant  Plant  Pathologist. 

T.  F.  HUNT,  B.S.,  Assistant  Plant  Pathologist. 

R.  E.  MAN  SELL,  Assistant  in  Horticulture,  in  charge  of  Central  Station  Grounds. 

G.  R.  STEWART,  B.S.,  Assistant  in  Station  Chemical  Laboratory. 

— ,  Assistant  in  Soil  Laboratory. 
RALPH  BENTON,  B.S.,  Assistant  in  Entomology. 
LUDWIG  ROSENSTEIN,  Laboratory  Assistant  in  Fertilizer  Control. 
ALFRED  TOURNIER,  Assistant  in  Viticulture. 
HANS  HOLM,  Student  Assistant  in  Zymology. 
A.  J.  GAUMNITZ,  Assistant  in  Cereal  Laboratory. 
J.  C.  BRADLEY,  A.B.,  Assistant  in  Entomology. 

D.  L.  BUNNELL,  Clerk  to  the  Director.  ' 


JOHN  TUOHY,  Patron      ) 

J.  T.  BEARSS,  Foreman  }  Tulare  Sub-Station,  Tulare. 

J.  W.  MILLS,  Horticultural  Assistant  in  Southern  California,  Riverside. 

J.  W.  ROPER,  Patron         ) 

E.  C.  MILLER,  In  charge  }  Universitj  Forestry  Station,  Chico. 

ROY  JONES,  Patron  ) 

N.  D.  INGHAM,  Foreman  }  University  Forestry  Station,  Santa  Monica. 

VINCENT  J.  HUNTLEY,  Foreman  of    California  Poultry  Experiment  Station,  Peta- 
luma. 

The  Station  publications   (REPORTS  AND  BULLETINS),  so  long  as 
available,  ivill  be  sent  to  any  citizen  of  the  State  on  application. 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE. 


Fungous  Diseases  of  the  Vine.  California  is  peculiarly  fortunate 
in  its  freedom  from  most  of  the  serious  fungous  vine  diseases  which 
add  so  much  to  the  expense  and  uncertainty  of  grape  growing  in  most 
countries.  Peronospora,  Black  Rot,  and  Anthracnose  are  here  quite 
unknown.  Of  the  four  most  serious  fungous  diseases  which  attack  the 
above-ground  portions  of  the  vine,  these  three  are  the  most  to  be  feared, 
as  they  are  not  only  capable,  if  neglected,  of  destroying  the  whole  crop 
of  a  vineyard,  but  require  the  utmost  vigilance  and  much  troublesome 
treatment  with  winter  washes  and  summer  sprays  to  hold  them  in 
check.  Their  absence  makes  quite  unnecessary  the  swabbing  of  the 
dormant  vines  with  sulfate  of  iron  and  the  spraying  of  the  growing 
vines  with  Bordeaux  mixture  which  are  adopted  here  by  some  vine- 
yardists  who  have  learned  the  practice  in  Europe  or  the  Eastern  States 
where  it  is  necessary. 

On  the  other  hand,  the  remaining  serious  fungous  disease — Oidium 
— exists  in  all  parts  of  California.  From  one  point  of  view,  this  is  the 
most  serious  disease  of  the  four,  as,  if  uncontrolled,  it  is  capable  of 
spreading  more  universally  through  the  vineyards  and  of  absolutely 
destroying  the  crops  in  nearly  all.  From  another  point  of  view,  it  is 
the  least  to  be  feared,  as  it  is  possible  to  control  it  completely,  at  least 
fti  most  parts  of  California,  by  much  simpler  and  less  expensive  meth- 
ods than  are  needed  for  the  others  mentioned. 

Introduction  of  Oidium  into  Europe.  With  the  exception  of  An- 
thracnose, which  is  a  native  of  Europe,  all  these  diseases  originated  on 
the  wild  vines  of  the  Eastern  and  Central  parts  of  the  United  States. 
Peronospora  and  Black  Rot  are  comparatively  recent  introductions 
into  Europe.  The*  former  was  observed  for  the  first  time  in  1878,  the 
latter  not  until  1885.  The  Oidium  was  first  noted  in  Europe  about 
1845,  when  an  English  gardener  named  Tucker  found  it  in  graperies 
at  Margate,  near  the  mouth  of  the  Thames.  It  was  discovered  two 
years  later  in  the  hot-houses  of  Paris  and  Belgium. 

Severity  of  the  Disease  in  Europe.  From  this  time  it  spread  rap- 
idly, until  by  1851  it  had  reached  every  grape-growing  country  of 
Europe.  The  amount  of  injury  done  by  the  disease  was  enormous  and 
increased  every  year,  reaching  its  maximum  in  France  about  1854.  In 


316  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION. 

this  year  it  reduced  the  crop  of  grapes  in  France  over  75  per  cent.,  in 
many  districts  totally  destroying  the  crop. 

Discovery  of  the  Utility  of  Sulfur.  After  1854,  the  grape  growers 
of  France  commenced  to  learn  how  to  control  the  disease.  The  use  of 
sulfur  for  this  purpose,  discovered  and  perfected  between  1850  and 
1853,  soon  became  general,  and  by  1859  the  crop  of  grapes  had  reached 
its  normal  volume  in  France.  The  effect  of  Oidium  in  diminishing  the 
crop  and  the  effect  of  sulfur  in  controlling  the  disease  in  one  depart- 
ment of  France  is  well  shown  by  fig.  1.  This  figure,  which  is  adapted 
from  one  published  in  the  nursery  catalogue  of  F.  Richter,  Montpellier, 
indicates  also  the  destruction  of  French  vineyards  by  Phylloxera  and 
their  rehabilitation  by  means  of  resistant  vines.  The  rapidity  with 
which  sulfur  enabled  the  French  grape  growers  to  reestablish  their 
vineyards  is  in  contrast  with  the  slowrer  process  of  controlling  the  phyl- 
loxera. In  three  or  four  years  after  the  use  of  sulfur  became  general 
in  the  Herault  the  crops  had  reached  their  normal  volume.  It  has 
taken  twenty  years  to  reestablish  the  same  vineyards  on  phylloxera 
resistant  stocks. 


OIDIUM         /  X       PHYLLOXERA 

SULFUR 


VINES 

RESISTANT 


Fig.  1.  Showing  (1)  the  reduction  of  crop  of  wine  in  the  Herault  from  3,900,000 
hectoliters  in  1850  to  1,000,000  hectoliters  in  1856  by  the  attack  of  Oidium; 
(2)  the  rapid  increase  of  crop  after  the  general  use  of  sulfur;  (3)  the  re- 
duction by  phylloxera  of  the  crop  from  15,200,000  hectos  in  1869  to  2,100,- 
000  hectos  in  1885;  and  (4)  the  gradual  increase  due  to  the  use  of  resistant 
vines. 

Damage  done  by  the  Disease  in  California.  In  California  the 
Oidium  has  never  produced  such  wide-spread  and  serious  injury  as 
that  indicated  above.  This  arises  principally  from  the  dryness  and 
heat  of  the  atmosphere  during  summer  in  most  of  our  grape-growing 
regions.  The  dryness  of  our  climate  is  undoubtedly  the  cause  of  our 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE.  317 

immunity  to  Peronospora,  Anthracnose,  and  Black  Rot,  and  while 
Oidium  requires  less  moisture  than  these  diseases  for  its  development, 
it  spreads  more  rapidly  and  is  more  difficult  to  control  in  a  moist  at- 
mosphere than  in  a  dry  one. 

At  the  same  time,  the  Oidium  does  far  more  harm,  even  in  Cali- 
fornia, than  is  usually  suspected,  and  in  certain  regions  and  certain 
seasons  may  totally  destroy  the  crop  and  diminish  the  crops  of  follow- 
ing years  by  injuring  the  vine. 

There  has  been  a  recrudescence  of  the  intensity  of  this  disease  both 
in  Europe  and  California  during  the  last  few  years.  This  is  due  in  all 
probability  not  to  any  change  in  the  fungus  or  of  the  seasons,  as  has 
been  suggested,  but  to  the  neglect  of  regular  sulfuring  by  the  grape 
growers,  who  have  become  careless  after  years  of  comparative  immu- 
nity due  to  more  or  less  general  treatment  for  the  disease. 

While  most  grape  growers  in  California  sulfur  their  vines  in  some 
way,  many  of  them  do  not  succeed  in  completely  controlling  the  disease 
and  are  often  doubtful  of  the  utility  of  the  treatment.  Where  good 
sulfur  does  not  give  immunity  it  is  because  it  has  not  been  applied  in 
the  right  way  or  at  the  right  time.  Many  growers  who  do  succeed  in 
keeping  their  vines  free  from  Oidium  do  so  at  the  expense  of  far  more 
sulfur  and  labor  than  are  necessary. 

The  main  object  of  this  bulletin,  therefore,  is  to  point  out  the  meth- 
ods of  control  which  have  been  generally  found  the  best  and  least 
costly. 

DESCEIPTION  OF  THE  DISEASE. 

Relationships  of  tJie  Disease.  This  disease,  usually  called  Mildew 
in  California,  is  caused  by  a  fungus  belonging  to  the  same  group  as  the 
fungi  which  cause  the  mildews  of  roses,  hops,  beans,  and  apples  and  is 
generally  referred  to  as  Oidium  in  Europe.  The  disease  known  as 
Mildew  or  Peronospora  in  Europe  and  the  East  is  totally  different  and 
caused  by  a  fungus  of  very  different  character.  In  order  to  distinguish 
the  two,  the  Oidium  is  sometimes  called  Powdery  Mildew  and  the 
Peronospora,  Downy  Mildew.  As  only  one  exists  in  California,  the 
use  of  the  word  Mildew  should  lead  to  no  confusion,  though  perhaps  it 
is  best  to  adopt  Oidium  as  the  name  of  this  disease. 

Symptoms  and  Effect  on  the  Vine.  The  Oidium  attacks  all  her- 
baceous parts  of  the  vine, — leaves,  canes,  flowers,  and  fruit.  In  the 
spring,  the  young  leaves  which  are  attacked  show  at  first  whitish 
patches  about  one-quarter  of  an  inch  in  diameter  on  the  upper  or  lower 
surfaces.  (See  fig.  2.) 


318 


UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION. 


As  the  disease  progresses  these  patches  run  together  until  a  large 
part  of  the  surface  of  the  leaf  may  be  covered  with  a  grayish  white 
mildew.  The  leaf  ceases  to  grow  and  curls  up  towards  its  upper  sur- 
face. (See  figure  on  cover.) 


Fig.  2.     White  patches  of  Oidium  on  upper  surface  of  young  leaf. 

As  the  shoots  lengthen,  the  canes  may  be  attacked  in  the  same  way. 
The  patches  of  mildew  appear  usually  near  the  bases  of  the  canes  and 
are  difficult  to  see  until  they  acquire  the  gray  tint.  In  severe  cases,  the 
fungus  may  completely  cover  the  whole  surface  of  the  cane,  but  it  is 
usually  confined  to  patches.  If  these  patches  are  rubbed  the  fungus 
comes  off  completely.  The  places  where  it  has  been,  however,  will  turn 
dark  later  owing  to  injuries  to  the  superficial  cells  of  the  bark.  (See 
%  3.) 


Fig.  3.     Blackening  of  canes  due  to  Oidium. 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE. 


319 


These  marks,  at  first  brown,  later  black,  are  usually  branching  or 
fern-like  in  form,  showing  the  points  of  attack  of  the  fungus.  If  the 
canes  are  attacked  when  young,  they  fail  to  mature  properly  and  often 
turn  black  over  their  whole  surface.  It  is  this  form  of  Oidium  which 
has  sometimes  been  mistaken  for  Anthracnose  in  California. 

Later,  the  blossoms  and  fruit  may  be  attacked.  When  the  blossoms 
are  attacked  they  fail  to  set,  and  if  the  berries  are  attacked  when  very 
small,  they  will  fail  to  develop  and  will  drop  off.  If  the  fruit  reaches 
nearly  full  size  before  being  affected,  it  continues  to  develop,  but  irreg- 
ularly. The  parts  of  the  epidermis  injured  by  the  fungus  become  hard- 
ened and  cease  to  grow.  This  results  in  irregularity  in  the  form  of  the 
berry  and  in  severe  cases  in  cracking.  (See  fig.  4.) 


Fig.  4.     Berries  badly  affected  and  cracked.     (After  Foex.) 

If  this  cracking  occurs  early,  the  grapes  dry  up  completely  before 
ripening.  If  later,  they  may  develop  sugar  and  can  be  used  for  wine 
making,  but  the  crop  is  diminished  in  volume.  In  moist  seasons  the 
berries  which  are  cracked  usually  become  the  prey  of  blue  mould  and 
are  completely  destroyed. 

After  the  grapes  have  lost  the  green  color  due  to  the  presence  of 
chlorophyll  in  the  skin  and  have  commenced  to  ripen  they  are  not  at- 
tacked by  Oidium.  The  markings  and  blotches  which  are  often  seen 
on  ripe  grapes  are  due  to  injuries  .to  the  skin  caused  by  the  presence 
of  the  fungus  on  the  grapes  before  they  ripened.  If  the  attack  has  not 
been  early  or  serious  enough  to  prevent  the  grapes  reaching  normal 


320  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION. 

size  they  may  still  make  good  wine.  The  markings,  however,  are  very 
objectionable  on  table  and  raisin  grapes  and  decrease  their  value. 

Tokay  and  Muscat  grapes  often  show  the  dark,  fern-like  markings 
characteristic  of  the  disease  similar  to  those  shown  on  the  canes.  ( See 
fig.  3.)  When  abundant,  these  markings,  which  are  accompanied  by  a 
thickening  of  the  skin,  injure  the  appearance  of  the  raisins.  Where 
the  skin  of  the  Muscat  grape  has  been  attacked  by  Oidium  it  will  re- 
main smooth  after  drying  and  not  show  the  fine  wrinkling  character- 
istic of  the  finest  raisins. 

A  vine  of  which  the  leaves  are  badly  attacked  has  a  peculiar  color 
and  wilted  appearance.  (See  figure  on  cover.)  This  appearance  is 
only  shown  when  the  conditions  of  temperature  and  moisture  are  favor- 
able to  the  growth  of  the  fungus  on  the  exterior  leaves.  This  can  occur 
only  at  the  beginning  of  the  season  in  the  warmer  and  drier  parts  of 
the  State.  When  the  air  is  hot  and  dry  the  fungus  cannot  grow  on  the 
outer  leaves.  The  proper  favorable  conditions,  however,  may  still  exist 
in  the  interior  of  the  vine.  For  this  reason  vines  may  look  perfectly 
healthy  from  a  little  distance,  while  the  fruit  and  the  bases  of  the  canes 
may  be  covered  with  Oidium.  A  vine  which  is  badly  attacked  has  a 
moldy  smell  readily  perceptible  to  many  people. 

DESCRIPTION  OF  THE  FUNGUS. 

Mode  of  Attack.  The  botanical  name  of  the  fungus  is  Uncinula 
spiralis  (Berkeley  and  Cooke),  and  it  belongs  to  the  family  or  group 
of  Erysipheae.  All  the  members  of  this  family  are  parasites  which 
live  upon  the  outer  surfaces  of  leaves  and  other  green  organs  of  plants. 
The  white  "mildew"  which  they  form  on  these  surfaces  consists  of  the 
branching  threads  or  mycelium,  which  constitute  the  vegetative  body 
of  the  fungus.  This  mycelium  grows  only  on  the  surface,  unlike  the 
mycelia  of  Peronospora  and  other  parasitic  fungi  which  enter  the  tis- 
sues of  the  host  plant.  It  obtains  its  nourishment  from  the  epidermal 
cells  of  the  plant  attacked,  by  means  of  suckers — haustoria — which 
penetrate  these  outer  cells.  The  outer  cells  thus  attacked  become  dark 
colored.  The  fact  that  the  Oidium  does  not  penetrate  the  tissues  of  the 
vine  much  facilitates  its  control  and  renders  its  destruction  possible  at 
any  stage  without  injury  to  the  host  plant  from  the  remedies  applied. 

Summer  Form  of  the  Fungus.  The  mycelial  threads  of  the  Unci- 
nula spiralis  are  extremely  fine — not  over  two  ten-thousandths  of  an 
inch  in  diameter.  They  elongate  afnd  grow  over  the  surface  to  which 
they  are  attached  by  their  haustoria  and  at  intervals  send  out  upright 
branches — hyphae — thirty  to  forty  ten-thousands  of  an  inch  long. 


OIDIUM  OB  POWDERY  MILDEW  OF  THE  VINE. 


321 


Fig.  5.     Various  forms  of  Uncinula  spiralis. 
I,  II.     Perithecia  showing  /,  appendages,  and  a,  asci. 

III.     Summer  form  showing  m,  mycelium;  t,  hyphae;  c,  conidia;  and  h,  haustoria. 
IV.     Group  of  asci  removed  from  perithecium  emitting  s,  ascospores.     (Ill  and 

IV,  after  Viala.) 

V.     Summer  form  of  Oidium  as  it  appears  on  surface  of  leaf. 
VI.     Ditto  showing  effect  of  sulfur  (d).     (V  and  VI,  after  Mares.) 


322  UNIVERSITY   OF  CALIFORNIA EXPERIMENT  STATION. 

These  hyphae  are  somewhat  thicker  than  the  mycelial  threads,  grad- 
ually increasing  in  diameter  from  the  bottom  to  the  top  until  they 
become  two  or  three  times  as  thick  as  the  threads  from  which  they 
arise.  Cross  partitions  divide  the  hyphae  into  several  cells,  the  upper- 
most of  which  finally  becomes  detached  and  forms  a  conidium  or 
summer  spore.  The  hypha  continues  to  grow  and  tne  second  cell  de- 
velops into  another  conidium.  This  process  continues  as  long  as  the 
conditions  are  favorable  throughout  the  summer,  each  hypha  produc- 
ing a  large  number  of  conidia.  These  conidia  are  egg-shaped  and 
measure  about  5  X  12  ten-thousandths  of  an  inch. 

"When  a  conidium  falls  on  a  suitable  part  of  the  vine  it  sends  out  a 
germinating  tube  which  fixes  itself  by  haustoria  and  grows  into  a  new 
mycelium  which  in  turn  produces  more  summer  spores.  (See  fig.  5, 
IIIc.) 

In  this  way,  all  the  green  parts  of  a  whole  vine  may  finally  be 
covered  Avith  a  coating  of  mycellium,  hyphae,  and  conidia,  which  to- 
gether form  the  whitish  or  grayish  matter  we  know  as  "Mildew"  or 
Oidium. 

Winter  or  Resting  Forms.  In  the  autumn  another  form  of  the 
fungus  is  often  produced.  Among  the  felted  threads  of  the  mycelium 
may  be  seen  with  the  unaided  eye  numerous  round  black  bodies,  which 
are  perithecia,  or  receptacles  containing  the  spores.  These  bodies  have 
an  average  diameter  of  about  %50  of  an  inch,  which  is  about  one-third 
the  diameter  of  the  dot  of  an  i  in  the  print  of  this  bulletin.  (See  fig. 
6,,A,B.) 

Under  the  microscope  they  are  seen  to  vary  in  color  from  yellow 
when  unripe  to  nearly  black  when  mature.  (.See  fig.  7.) 


'     "*  

A.  x> 

Fig.  6.     Photomicrographs  of  Perithecia  on  Surface  of  Leaf. 
A.  Magnified  8  times.     B.  Magnified  35  times. 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE.  323 

A  mature  perithecium  consists  of  a  nearly  spherical  case  containing 
from  four  to  eight  cell-sacks  called  asci.  The  walls  of  this  case  are 
strong  and  resistant  to  cold  and  other  unfavorable  conditions  which 
destroy  the  summer  forms  of  the  fungus.  They  are  made  up  of  thick 
polygonal  cells  and  form  a  very  efficient  protection  to  the  asci.  An 
ascus  contains  from  four  to  six  spores.  (See  figs.  8  and  5,  IV.) 

Each  penthecium  is  furnished  with  10  to  25  hair-like  appendages 
of  about  the  same  thickness  as  the  mycelial  threads  and  from  one-one 
hundredths  to  one-fiftieth  of  an  inch  in  length.  These  appendages  are 
divided  by  several  cross  partitions  and  are  coiled  at  the  free  end.  They 
consist  usually  of  a  single  thread,  but  occasionally  branch.  (See  fig. 
5,  II.) 

The  perithecia  remain  upon  the  canes^  and  leaves  or  in  the  soil  until 
the  return  of  warm  weather  in  spring.  As  soon  as  the  temperature 
becomes  sufficiently  high,  the  walls  of  the  perithecia  .break  open  and 
allow  the  asci  to  emit  their  spores.  These  spores,  when  they  reach  a 
leaf  or  growing  shoot,  germinate  in  the  same  manner  as  the  summer 
spores  and  give  rise  to  a  new  generation  of  Oidium. 

The  perithecia  do  not  all  emit  their  spores  at  the  same  time  owing 
to  the  different  conditions  of  the  places  in  which  they  have  passed  the 
winter.  Some  may  even  remain  in  the  soil  until  the  following  spring. 
Perithecia  have  been  shown  to  contain  spores  capable  of  germination 
eighteen  months  after  their  formation.1  It  is  therefore  impossible  to 
completely  exterminate  the  fungus  in  a  vineyard  in  one  year,  however 
thorough  the  treatment.  Burying  the  perithecia  by  plowing-in  simply 
aids  in  their  preservation  and  they  are  ready  to  cause  a  new  infection 
two  years  later  when  brought  to  the  surface  again  by  later  plowing. 
Although  the  Oidium  was  introduced  into  Europe  as  early  as  1845,  it 
was  not  until  1892  that  the  winter  form  of  the  fungus  was  found  there. 
It  was  for  this  reason  uncertain  until  that  time  that  our  Oidium  and 
that  of  Europe  were  identical. 

It  seems  probable  that  the  fungus,  under  some  conditions,  carl  pass 
the  winter  in  the  conidial  or  summer  form.  At  all  events,  in  certain 
districts  the  perithecia  have  never  been  found  and  are  therefore  absent 
or  very  rare.  They  are  very  rare  in  the  interior  valleys  of  California. 
On  the  other  hand,  they  are  produced  in  immense  numbers  on  vines 
within  the  influence  of  the  summer  ocean  fogs.  At  Berkeley  it  is  com- 
mon to  find  thousands  of  them  on  every  leaf  and  cane  of  a  vine.  More 
than  100,000  perithecia  have  been  counted  on  the  upper  surface  of  a 


1  Revue  de  Viticulture,  No.  655,  p. 


324 


UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION. 


**Hr*» 


*  -^ 


Fig.  7.  Photomicrograph  of  Perithecia  taken  from  Vine  Leaf;  magnified  30  times. 
The  light  colored  bodies  are  immature  perithecia;  the  dark  colored,  mature 
peritliecia  which  have  been  burst  open  by  pressure. 


Fig.  8.  Photomicrograph  of  Perithecia  magnified  about  200  times.  One  perithe- 
cium  has  been  broken  by  pressure  and  the  asci  are  partially  pressed  out. 
The  winter  spores  can  be  seen  through  the  transparent  walls  of  the  asci. 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE.  325 

single  leaf,  and  as  each  perithecium  contains  fifty  or  more  spores,  the 
number  produced  on  a  single  vine  may  be  hundreds  of  millions. 

In  Europe  they  are  formed  in  September  and  October.  In  Berke- 
ley they  are  found  in  abundance  as  early  as  the  middle  of  June.  Their 
formation  seems  to  depend  on  weather  conditions.  If  after  a  period 
of  warm,  moist  weather,  which  has  produced  an  abundant  growth  of 
mycelium,  the  temperature  suddenly  falls  to  near  the  lowest  limit  for 
the  growth  of  the  fungus  (50°  P.),  they  are  produced  rapidly  and  in 
great  numbers.  These  are  weather  conditions  which  often  occur  at 
Berkeley  and  in  the  valleys  nearest  the  coast. 

In  the  interior  very  different  conditions  exist.  The  fungus  may 
grow  abundantly  during  the  spring  and  early  summer,  but  there  is 
seldom  any  fall  of  temperature  at  this  season  sufficient  to  cause  the 
production  of  the  winter  spores.  As  the  summer  advances,  the  air  be- 
comes too  hot  and  dry  for  the  fungus,  so  that  by  the  time  the  cooler 
weather  of  October  arrives,  most  of  the  Oidium  has  disappeared  and 
the  abundant  growth  of  strong  mycelium  .which  is  necessary  does  not 
exist. 

CONDITIONS  FAVORING  THE  DISEASE. 

Variations  in  Susceptibility  of  Varieties.  There  is  considerable 
difference  in  the  susceptibility  of  various  varieties  of  vines  and  there- 
fore in  the  ease  with  which  they  can  be  kept  free  from  the  disease.  All 
species  of  American  vines, — Labrusca,  Riparia,  Rupestris,  etc., — are 
much  less  severely  attacked  than  the  European  varieties  of  Vitis 
vinifera. 

Among  the  latter  there  exist,  however,  various  degrees  of  suscepti- 
bility. Of  the  varieties  cultivated  in  California,  those  most  easily  and 
severely  attacked  are  the  Carignane,  Flame  Tokay,  Muscat  of  Alex- 
andria, Gutedel,  Cabernet,  Riesling,  Clairette,  Folle  blanche,  Ugni- 
blanc,  and  Petite  Sirah.  Tlie  more  resistant  are  the  Beclan,  Duriff, 
Malbec,  Mataro,  Grenache,  Alicante  Bouschet,  Petit  Bc/tischet,  Ara- 
mon,  Mourastel,  Vernaccia,  and  Marsanne.  All  varieties,  however,  are 
capable  of  being  severely  injured  if  the  weather  conditions  favor  the 
growth  of  the  fungus.  The  Beclan  and  Duriff  are  perhaps  the  most 
resistant  of  all  mentioned  and  are  for  this  reason  very  valuable  vari- 
eties to  plant  in  localities  within  the  influence  of  the  summer  ocean 
fogs. 

Temperature  and  Moisture  Conditions.  The  fungus  requires  cer- 
tain degrees  of  temperature  and  moisture  for  its  development.  It 
grows  most  vigorously  and  abundantly  in  sheltered  shady  positions. 


326  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

For  this  reason,  vines  on  walls  or  trellises  are  more  liable  to  attack, 
while  vines  out  in  the  open  vineyard,  especially  where  they  are  sub- 
jected to  the  full  action  of  the  wind,  are  less  severely  affected. 

Though  the  fungus  requires  less  moisture  than  most  others  causing 
diseases  of  the  vine,  it  will  not  grow  in  an  atmosphere  that  is  too  dry. 
In  the  drier  regions  of  California  it  is  much  less  frequent  than  along 
the  coast.  Vines  in  low  places  or  near  the  banks  of  rivers  or  irrigation 
canals  are  often  attacked  when  the  rest  of  the  vineyard  is  free.  Rains 
or  fogs  in  the  spring  or  early  summer  are  very  favorable  to  the  growth 
of  Oidium,  especially  if  they  are  accompanied  by  a  warm  temperature. 

The  fungus  will  grow  at  a  wide  range  of  temperature.  Below  50° 
F.,  however,  its  growth  is  arrested  and  for  15  or  20  degrees  above  this 
its  growth  is  slow.  Above  75°  F.,  its  growth  is  rapid  and  reaches  its 
maximum  at  about  90°  F.  or  95°  F.,  providing  the  air  remains  suffi- 
ciently moist.  At  about  100°  F.  it  ceases  to  grow  and  at  few  degrees 
above  this  it  is  killed. 

These  considerations  explain  the  different  ways  in  which  the  fungus 
attacks  vines  in  different  localities  and  in  different  seasons. 

In  the  coast  regions,  during  the  spring,  the  Oidium  attacks  most 
severely  the  outer  leaves  and  the  ends  of  shoots  on  the  south  and  east 
sides  of  the  vine.  The  parts  of  the  vine  which  are  shaded  do  not  be- 
come sufficiently  warm  for  the  growth  of  the  fungus.  As  the  season 
progresses  and  the  temperature  of  the  air  rises,  the  west  and  north 
sides  of  the  vine  become  affected  and  finally,  by  midsummer,  the  fun- 
gus is  able  to  grow  on  all  parts  of  the  vine  and  the  bunches  and  bases 
of  the  canes  are  attacked.  Very  near  the  coast  all  parts  of  the  vine  are 
liable  to  attack  throughout  the  summer,  but  in  the  main  coast  valleys, 
the  fungus  is  usually  confined  to  the  interior  of  the  vine  after  the 
middle  or  end  of  June. 

In  the  interior  valleys,  it  is  very  unusual  to  find  the  outer  leaves  of 
the  vines  attacked  at  any  season.  Vines  which  are  much  shaded  by 
neighboring  trees  or  buildings,  however,  may  be  attacked  in  the  late 
spring  in  a  way  similar  to  that  which  occurs  nearer  the  coast.  Usually 
the  fungus  is  first  seen  at  or  just  before  blossoming  time  and  its  attacks 
are  confined  to  the  canes,  flower  bunches,  and  interior  leaves.  This 
early  attack  sometimes  causes  a  great  loss  of  crop  even  when  to  a  cur- 
sory examination  the  vine  appears  perfectly  healthy. 

During  the  summer,  the  dry  air  and  great  heat  prevent  the  devel- 
opment of  the  fungus,  and  in  fact  destroy  the  greater  part  of  it.  The 
crop,  however,  may  be  seriously  injured  before  sufficiently  hot  weather 
arrives.  Most  varieties  of  grapes  in  the  hotter  parts  of  the  Sacra- 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE.  327 

mento  and  San  Joaquin  valley  will  ripen  their  fruit  perfectly  if  they 
escape  the  spring  infection.  Late  ripening  varieties,  however,  such  as 
some  of  the  table  grapes,  may  be  attacked  during  the  cooler  weather  of 
autumn  and  in  some  seasons  any  variety  growing  vigorously  in  moist 
places  may  be  attacked  during  summer  and  autumn. 

CULTUEAL  METHODS  OF  CONTEOL. 

The  Oidium  can  be  checked  to  some  slight  extent  by  cultural  meth- 
ods. Anything  which  permits  the  sun  and  air  to  get  to  all  parts  of 
the  vine  more  completely  will  lessen  the  danger  from  mildew.  Rows 
of  trees  which  shade  the  vines  on  the  south  side  can  often  be  removed 
with  advantage.  Vines  planted  wide  apart  are  less  subject  to  the  dis- 
ease, as  they  dry  off  more  quickly  in  the  morning.  For  the  same  reason, 
the  rows  of  trellised  vines  should  run  north  and  south  in  order  to  facil- 
itate the  drying  action  of  the  rising  sun.  Low  trellised  vines'  are  often 
less  subject  to  Oidium  than  ordinary  vines,  as  the  foliage  is  spread 
over  a  larger  surface  and  not  massed  around  the  head  as  in  vase  prun- 
ing. On  the  other  hand,  high  trellised  vines  are  usually  more  subject, 
as  the  wind  and  sun  do  not  penetrate  them  so  well. 

Drainage  of  the  wet  places  in  a  vineyard  and  methods  of  pruning 
and  training  which  spread  the  vine  out  so  that  no  part  is  surrounded 
by  still  moist  air  will  tend  to  diminish  the  intensity  of  the  disease. 

SULFUE  TEEATMENT. 

Mode  of  Action.  No  cultural  method  is  capable  of  completely  pro- 
tecting the  vines  from  Oidium  except  under  the  most  favorable  condi- 
tions and  with  the  most  resistant  varieties.  Some  special  treatment, 
therefore,  is  nearly  always  necessary.  Of  all  the  methods  tried,  there 
is  none  so  effective  as  the  dusting  of  powdered  sulfur  over  the  vines. 

Sulfur  acts  by  means  of  the  fumes  it  gives  off  when  the  tempera- 
ture is  sufficiently  high.  These  fumes  destroy  the  mycelium  and 
summer  spores  of  the  fungus,  and  if  present  in  sufficient  abundance 
will  destroy  every  vestige  of  Oidium  in  the  vineyard  with  the  exception 
of  the  perithecia. 

The  exact  nature  of  the  fumes  given  off  is  uncertain.  Some  authors 
believe  them  to  consist  of  sulfurous  acid  gas  identical  with  that  pro- 
duced by  the  burning  of  sulfur  and  to  be  due  to  slow  oxidation.  The 
odor  perceptible  on  a  hot  day  in  a  sulfured  vineyard,  however,  has  not 
the  pungent  nature  characteristic  of  the  fumes  of  burning  sulfur,  but 
resembles  that  of  hydrogen  sulfid,  which  other  authors  believe  to  be 


328  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

the  active  substance.  Other  investigators  claim  that  the  active  fumes 
are  simply  vapors  of  pure  sulfur  volatilized  by  the  high  temperature. 

The  active  fumes,  whatever  their  nature,  are  given  off  in  effective 
quantities  only  after  the  temperature  of  the  air  reaches  about  75°  F. 
Above  this  point  they  are  given  off  the  more  actively  the  higher  the 
temperature.  Below  75°  F.  the  fungus  grows  very  slowly  and  the 
sulfur  fumes  are  little  needed,  and,  as  the  air  warms  up  to  a  temper- 
ature at  which  the  fungus  grows  rapidly,  the  fumes  are  given  off  in 
greater  abundance. 

The  lower  the  temperature  the  more  slowly  the  fungus  is  affected. 
If  the  highest  shade  temperature  of  the  day  is  between  75°  and  80°  F., 
it  will  require  from  seven  to  eight  days  to  destroy  all  the  mycelium. 
When  the  temperature  rises  to  90°-95°  F.,  the  fungus  commences  to 
show  signs  of  injury  in  24  hours  and  in  four  or  five  days  is  destroyed. 
If  the  thermometer  rises  to  above  100°  F.  in  the  hottest  part  of  the 
day.  one  or  two  days  are  sufficient  to  completely  rid  the  vineyard  of 
the  disease. 

In  order  to  obtain  these  perfect  results,  however,  the  sulfur  must 
be  applied  to  every  part  of  the  vine.  The  nearer  a  spore  or  a  piece  of 
mycelium  is  to  a  particle  of  sulfur,  the  more  quickly  it  is  killed.  Ex- 
cept in  the  hottest  weather,  the  sulfur  on  one  leaf  is  almost  without 
effect  on  the  fungus  on  a  neighboring  leaf.  The  utility,  indeed  the 
necessity,  of  a  perfect  distribution  of  the  sulfur,  especially  in  compar- 
atively cool  weather,  is  apparent. 

The  air  is  always  hottest  near  the  soil,  and  sulfur  placed  on  the  soil 
should  give  off  more  abundant  fumes.  Practice  has  shown,  however, 
that  sulfur  placed  in  this  position  has  almost  no  effect  on  the  Oidium 
except  in  extremely  hot  weather.  In  such  weather,  sulfur  is  hardly 
ever  needed  in  California,  as  it  is  usually  accompanied  by  such  a  dry 
condition  of  the  air  that  the  fungus  is  killed  without  the  aid  of  sulfur 
fumes. 

In  exceptional  cases,  as  for  instance  where  very  vigorous  vines  are 
growing  in  very  moist  places  in  the  irrigated  regions  or  when  un- 
usually hot  weather  occurs  in  the  coast  regions,  the  air  may  be  moist 
enough  for  the  growth  of  Oidium  even  when  the  temperature  rises  to 
considerably  above  100°  F.  In  such  cases  it  is  sometimes  desirable  to 
sprinkle  the  sulfur  on  the  ground  instead  of  on  the  vines.  The  reason 
of  this  is  that  if  the  air  is  sufficiently  hot  the  sulfur  may  injure  both 
the  fruit  and  the  leaves  of  the  vines.  The  fruit  and  leaves  may  be 
spotted  and,  in  severe  cases,  may  fall  completely  or  in  part.  Such 
effects  are  to  be  feared,  however,  only  when  the  temperature  exceeds 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE.  329 

110°  F.,  or  with  varieties  particularly  susceptible  to  sulfur  fumes, 
such  as  Isabella,  Othello,  and  certain  other  American  varieties  and 
hybrids. 

If  the  earlier  sulfurings  are  done  properly,  however,  it  will  seldom 
be  necessary  to  treat  the  vines  in  such  weather  and  we  may  consider 
that  the  sulfur  which  goes  on  the  ground  is  almost  completely  wasted. 
Effects  of  Sulfur  on  the  Vine,  Fruit,  and  Wine.  The  effect  of 
sulfur  on  the  vine  is  in  no  way  injurious  except  under  the  conditions 
already  noted.  On  the  contrary,  most  observers  concur  in  noting  im- 
provement in  the  health  and  vigor  of  the  vines  after  sulfuring  irre- 
spective of  the  control  of  mildew.  Whether  this  is  due  to  some  stimu- 
lating action  of  the  sulfur  on  the  foliage  or  to  its  action  on  the  plant 
food  in  the  soil  is  in  doubt. 

The  favorable  influence  of  sulfuring  the  vines,  while  in  blossom,  on 
the  setting  of  the  fruit  is  even  more  generally  recognized.  If  Oidium 
is  present,  this  is  easily  accounted  for  by  the  prevention  of  the  action 
of  the  fungus  on  the  blossoms.  The  effect,  however,  is  noticed  even 
when  no  Oidium  exists  in  the  vineyard.  The  tendency  of  many  vari- 
eties to  " coulure," — dropping  their  blossoms  without  setting, — can  be 
lessened  by  vigorous  sulfuring  during  the  blossoming  period.  Whether 
this  is  due  to  a  stimulation  of  the  floral  organs  under  the  action  of  the 
.sulfur,  to  the  destruction  of  unrecognized  fungi  on  the  blossoms,  or 
merely  to  the  mechanical  action  of  the  current  of  air  produced  by  the 
blowers  in  promoting  pollination  has  never  been  determined. 

Heavy,  late  sulfuring  may  introduce  notable  quantities  of  sulfur 
into  the  wine.  This  sulfur  is  apt,  under  the  influence  of  the  yeast,  to 
give  a  disagreeable  odor  of  sulfureted  hydrogen  to  the  wine.  This 
odor  is  usually  temporary  and  disappears  after  a  few  rackings  of  the 
wine.  When  the  sulfuring  is  done  with  a  suitable  machine,  however, 
.so  little  sulfur  is  placed  upon  the  grapes  that  this  danger  is  not  to  be 
feared. 

Properly  sulfured  vines  ripen  their  grapes  from  7  to  10  days  earlier 
than  those  attacked  by  Oidium.  This  is  probably  due  to  the  better 
health  of  the  vines,  which  allows  the  fruit  to  develop  more  quickly  and 
more  perfectly. 

Proper  time  and  Weather  for  Sulfuring.  The  time  of  day  at  which 
the  sulfur  is  applied  is  of  little  importance,  provided  the  weather  is 
suitable.  It  may  be  applied  when  the  leaves  are  dry  or  when  they  are 
moist  with  dew.  It  is  less  effective,  however,  if  the  leaves  are  very  wet, 
as  the  drops  of  water  have  a  tendency  to  gather  the  sulfur  into  patches 
-and  leave  parts  of  the  leaf  untreated. 


330  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

It  is  impossible  to  do  the  work  perfectly  in  a  high  wind,  but  a 
gentle  breeze  is  an  aid  in  making  the  sulfur  penetrate  to  all  parts  of 
the  vine. 

Rain  or  very  heavy  and  continued  winds  following  immediately 
after  the  sulfuring  will  remove  most  of  the  sulfur  before  it  has  pro- 
duced the  desired  effect  on  the  fungus,  and  the  treatment  must  be  re- 
peated. Each  sulfuring  should  be  followed  by  from  one  to  four  days 
of  warm  weather  before  the  sulfur  is  removed  by  rain  or  wind.  One 
or  two  days  at  or  about  90°  F.  to  95°  F.,  maximum  shade  temperature, 
or  four  or  five  days  between  85°  F.  and  90°  F.  will  usually  give  satis- 
factory results.  If  rain  comes  before  the  sulfur  has  been  subjected  to 
such  temperature,  the  vines  must  be  resulfured. 

As  already  noted,  sulfuring  in  excessively  hot  weather  should  be 
avoided  on  account  of  the  danger  of  burning  grapes  or  foliage.  For 
the  same  reason,  any  cultivation  or  other  disturbance  of  the  vines 
should  be  avoided  in  hot  weather  immediately  following  the  application 
of  sulfur. 

Proper  Season  for  Sulfuring.  The  proper  season  for  sulfuring  will 
depend  on  the  number  of  sulfurings  needed.  This  number  will  differ- 
according  to  locality,  weather,  variety,  and  the  exposure  of  the  vine- 
yard and  will  vary  from  one  to  three  in  the  interior  valleys  to  from 
two  to  five  in  the  coast  valleys,  or  even  as  high  as  six  or  seven  with 
susceptible  varieties,  in  bad  seasons  in  close  proximity  of  the  coast. 

The  most  necessary  and  effective  sulfuring  of  all,  and  one  which 
should  never  be  omitted  under  any  conditions,  is  at  the  time  when  the 
vines  begin  to  open  their  blossoms.  Even  with  the  most  resistant  vari- 
eties, in  the  least  affected  districts,  this  sulfuring  should  be  applied. 
Even  where  there  is  little  or  no  danger  of  Oidium,  the  gain  in  better- 
setting  of  the  fruit  has  been  so  frequently  demonstrated  that  it  amply 
repays  the  outlay.  As  all  varieties  do  not  blossom  at  the  same  time,  the 
mixing  of  varieties  in  the  same  block  should  be  avoided,  for  this  and 
other  reasons. 

Number  of  Treatments.  In  the  interior,  if  this  sulfuring  were  reg- 
ularly and  universally  applied,  it  would  usually  be  sufficient.  As  many 
growers  totally  neglect  sulfuring,  however,  there  is  danger  of  reinfec- 
tion from  neighboring  vineyards  during  the  early  summer.  The  vines 
should  be  watched,  therefore,  and  upon  the  first  signs  of  Oidium,  a 
second  sulfuring  should  be  applied.  This  will  usually  be  at  the  time 
the  grapes  are  about  the  size  of  buckshot.  Later  than  this  there  is 
little  danger  usually,  as  the  air  becomes  too  hot  and  dry  for  the  growth 
of  the  fungus.  The  vines  should  be  watched,  however,  especially  those- 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE.  331 

in  moist  parts  of  the  vineyard — near  irrigation  ditches  or  in  the  shade 
of  trees.  Very  vigorous  vines  or  susceptible  varieties  in  cool  seasons 
also  may  exceptionally  require  another  sulfuring  just  before  the  grapes 
commence  to  color  or  to  soften.  These  late  sulfurings,  however,  are 
dangerous  in  the  hot  districts  for  reasons  already  given,  and  can  nearly 
always  be  avoided  if  the  earlier  treatments  are  applied  properly  and  in 
time. 

There  are  cases  where  it  is  advisable  even  in  the  interior  to  give  the 
vines  a  sulfuring  before  the  blossoming  time.  If  the  vines  were  badly 
attacked  during  the  previous  season  there  will  be  an  abundance  of 
spores  in  the  vineyard  and  much  injury  may  be  done  before  the  blos- 
soming time  if  the  spring  is  warm.  In  such  cases,  it  is  best  to  give  an 
early  sulfuring  at  the  time  the  vine  shoots  are  about  6  to  8  inches  long. 
For  this  sulfuring  it  is  very  necessary  to  choose  suitable  weather.  If 
unfortunately  this  treatment  is  followed  by  rain  or  continued  heavy 
winds  without  any  intervening  warm  days,  it  should  be  repeated. 

This  early  sulfuring  is  very  useful  also  in  destroying  the  mites 
causing  erinose?-  a  disease  which  often  does  considerable  damage  to  the 
vines  before  the  weather  is  warm  enough  for  very  rapid  growth  of 
Oidium.  The  erinose  attacks  with  particular  intensity  Mission  and 
Flame  Tokay. 

In  the  coast  valleys, — Sonoma,  Napa,  Santa  Clara,  etc., — two  sul- 
furings should  always  be  given ;  the  first  at  the  time  the  shoots  are 
from  6  to  8  inches  long.  This  treatment  might  be  omitted  in  dry,  well 
ventilated  situations  with  resistant  varieties,  if  sulfuring  were  univer- 
sally practised  throughout  the  district,  but  it  is  at  present  always  safer 
to  apply  it.  The  second  sulfuring  should  be  at  blossoming  time.  In 
dry  early  summers,  except  with  the  most  susceptible  varieties  such  as 
Carignane,  a  third  sulfuring  will  often  be  unnecessary.  The  vine 
should  be  carefully  watched,  however,  and,  on  the  first  appearance  of 
mildew,  sulfur  applied  again.  In  bad  seasons  a  fourth  sulfuring  just 
before  the  commencement  of  ripening  may  be  necessary.  By  watching 
the  parts  of  the  vineyard  which  experience  has  shown  to  be  the  most 
quickly  affected,  it  is  always  possible  to  control  the  disease  before  it 
has  done  any  serious  damage. 

After  the  grapes  have  commenced  to  ripen,  they  are  almost  safe 
from  the  attacks  of  Oidium,  but  it  is  a  mistake  for  this  reason  to  allow 
the  fungus  to  become  abundant  on  the  leaves,  as  it  may  in  warm,  moist 
autumns.  Though  such  a  late  attack  may  do  little  or  no  damage  to  the 


1  See  Bulletin  No.  136,  < '  The  Erinose  of  the  Vine. 


332  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

current  crop,  it  will  injure  the  buds  and  canes  on  which  the  crop  of 
the  following  year  depends.  Moreover,  it  is  this  late  growth  of  mildew 
which  produces  the  winter  spores  and  promotes  an  early  and  severe 
attack  of  the  disease  during  the  following  spring.  The  vines  therefore 
should  be  kept  free  from  Oidium  even  if  it  requires  a  sulfuring  after 
the  grapes  are  gathered. 

In  the  coast  districts  where  weather  conditions  similar  to  those  of 
Berkeley  exist,  even  three  sulfurings  will  seldom  be  sufficient  to  hold 
the  Oidium  completely  in  check.  "Where  the  springs  are  warm  and  the 
summers  comparatively  cool  and  moist,  as  along  the  coast  of  Santa 
Cruz,  the  fungus  finds  conditions  favorable  to  its  development  at  all 
times  of  the  year  when  the  vines  are  in  leaf.  In  such  locations  an  early 
sulfuring,  when  the  shoots  are  3  or  4  inches  long,  another  at  blossoming 
and  a  third  when  the  grapes  are  the  size  of  buckshot  are  always  neces- 
sary. If  these  are  thorough  and  there  are  no  neighboring  neglected 
vineyards  to  spread  continuous  reinfection,  certain  varieties  may  be 
kept  free  in  good  years  by  three  sulfurings.  It  will,  however,  usually 
be  necessary  to  interpolate  another  treatment  between  the  first  and 
that  at  blossoming  time  and  follow  the  third  with  one  or  two  supple- 
mentary treatments. 

Sulfuring  Young  Vines.  Young  vines,  whether  in  the  vineyard  or 
the  nursery,  should  not  be  neglected.  In  the  nursery  they  are  pecu- 
liarly susceptible  owing  to  their  nearness  to  each  other  and  to  the  moist 
air  near  the  irrigated  soil.  Autumn  sulfuring  is  nearly  always  useful 
in  this  case  to  keep  the  leaves  healthy  until  they  have  ripened  the  canes. 
Young  vines  during  the  first  year  in  the  vineyard  are  seldom  seriously 
injured  by  mildew,  but  it  is  advisable  to  sulfur  them  at  least  once  dur- 
ing the  early  summer. 

Methods  of  Applying  Sulfur.  From  what  has  been  said  of  the 
action  of  sulfur  on  the  fungus,  it  is  clear  that  thorough  distribution  is 
the  main  factor  in  its  effective  application.  Providing  we  get  some 
sulfur  on  every  part  of  every  vine  in  the  vineyard,  the  amount  we  use 
is  of  little  importance  in  controlling  the  disease. 

Whatever  the  fumes  may  be  which  are  given  off,  the  amount  of 
sulfur  used  in  producing  them  is  infinitesimal.  The  smallest  quantity 
of  sulfur  we  can  possibly  use  in  practice  is  amply  sufficient  if  we  ac- 
complish the  object  of  leaving  no  part  of  the  vine  untouched. 

On  a  properly  sulfured  vine  the  distribution  is  so  perfect  that  on 
close  examination  we  are  unable  to  find  a  square  inch  of  surface  free 
from  sulfur  grains.  On  the  other  hand,  if  on  looking  at  a  vine  from 
a  distance  of  twenty  feet  we  can  see  any  signs  of  the  sulfur  applied, 
more  than  enough  has  been  used. 


OIDIUM  OR  POWDERY  MILDEW  OF  T"HE  VINE.  333 

If  the  distribution  is  defective,  we  not  only  fail  to  free*  all  parts  of 
the  vine  from  the  Oidium  but  we  leave  enough  of  the  fungus  to  spread 
rapidly  through  the  vineyard  as  soon  as  the  sulfur  has  been  removed 
by  rain  or  wind.  Two  or  three  incomplete  sulfurings  which  fail  to 
reach  a  number  of  whole  vines  or  parts  of  vines  are  often  less  effective 
than  one  thorough  treatment  which  leaves  no  part  of  any  vinje  un- 
touched. 

The  methods  used  in  California  for  sulfuring  vines  are  the  fol- 
lowing : 

1.  Throwing  the  sulfur  on  the  vines  by  hand; 

2.  Distributing  by  perforated  cans  of  various  forms ; 

3.  Shaking  through  the  tissue  of  a  cloth  sack ; 

4.  Various  forms  of  hand  bellows ; 

5.  Various  forms  of  knapsack  bellows ; 

6.  Traction  sulfur  distributers. 

The  disease  can  be  completely  controlled  by  any  of  these  methods. 
They  differ  only  in  the  amount  of  labor,  sulfur,  and  care  necessary  in 
applying  them.  In  these  respects,  however,  they  differ  very  notably. 

1.  Throwing  on  by  hand  is  undoubtedly  the  most  laborious,  dis- 
agreeable, and  wasteful.     Something  like  90  per  cent,  or  more  of  the 
sulfur  is  wasted  because  most  of  it  goes  on  the  ground,  and  of  that 
which  goes  on  the  vine  a  few  leaves  usually  receive  the  bulk.    When 
the  vines  are  large,  if  all  parts  of  the  vine,  extremities  of  canes  and 
center  of  head,  are  properly  treated,  from  five  to  twenty  times  as  much 
sulfur  will  be  used  as  by  the  best  methods.    It  also  requires  more  time 
than  the  better  methods.     It  is  moreover  very  difficult  to  get  men  to 
sulfur  effectively  by  this  means  owing  to  the  large  amount  of  sulfur 
they  get  into  their  eyes  and  mouths.    They  are  naturally  apt  to  think 
more  of  protecting  themselves  than  of  destroying  the  mildew. 

2.  Distribution  from  perforated  cans  is  perhaps  the  commonest 
method  of  application.     It  is  a  little  better  than  hand  throwing,  but 
wastes  a  great  deal  of  sulfur.    With  large  vines  from  five  to  ten  times 
as  much  is  used  as  is  necessary.    It  is  very  difficult  to  reach  the  tops  of 
high  vines  with  the  ordinary  forms  of  cans.     Some  sulfur  cans  are 
made  with  a  long  handle,  which  obviate  this  defect  to  some  extent  but 
increase  the  difficulty  of  sulfuring  the  low  parts  and  center  of  the  vine. 

In  both  these  methods  it  is  unnecessary  to  use  the  best  brands  of 
sulfur,  as  with  complete  distribution  so  much  is  used  that  there  is 
always  enough  fine  material,  except  with  the  worst  grades,  to  do  the 
work.  Some  growers  mix  the  sulfur  with  lime,  ashes,  road  dust,  or 
some  inert  powder  to  save  sulfur.  The  main  objection  to  this  is  that 
it  involves  the  carrying  and  distribution  of  useless  material. 


334  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

3.  An  improvement  on  the  last  method  is  the  use  of  a  sack  from 
which  to  shake  the  sulfur  on  to  the  vine.    This  sack  should  be  made  of 
cloth  whose  texture  is  close  enough  to  permit  only  fine  particles  of 
sulfur  to  pass,  but  not  so  close  as  to  require  too  much  labor  in  shaking 
out  the  required  amount.    A  sack  about  14  inches  long  and  5  inches  in 
diameter,  holding  about  3  pounds  of  sulfur  when  half  full,  is  a  con- 
venient size.    Somewhat  tightly  woven  grain  sacks  of  good  quality  are 
suitable  material  from  which  to  make  them. 

Very  good  work  can  be  done  with  sacks  of  this  kind  while  the  vines 
are  small.  Their  main  defects  are  that  they  hold  very  little  and  much 
time  is  wasted  walking  to  the  sulfur  supply  to  fill  them.  They  wear 
out  very  quickly  and  the  work  with  them  is  laborious.  They  cannot  be 
used  while  the  vines  are  wet,  as  moisture  on  the  sacks  prevents  the 
sulfur  from  coming  out. 

For  large  and  high  vines  they  are  even  less  suitable  than  the  cans. 
It  is  almost  impossible  to  sulfur  any  part  of  a  vine  higher  than  the 
workman's  head. 

4.  The  use  of  small  hand  bellows  similar  to  that  shown  in  fig.  9,  b 
is  a  great  improvement  over  the  three  methods  just  described.     The 
distribution  of  the  sulfur  is  much  better,  the  workman  less  troubled  by 
the  sulfur,  and  every  part  of  the  vine  can  be  reached. 

The  main  defects  of  these  bellows  are  that  they  are  very  tiring  to 
the  hands  and  arms,  and  as  they  hold  little  sulfur  much  time  is  wasted 
in  filling  them.  While  not  so  wasteful  of  sulfur  as  the  above  methods, 
they  use  more  sulfur  than  is  necessary. 

5.  The  best  knapsack  bellows  are  a  great  improvement  on  the  hand 
bellows.     These  machines  are  known  as  "dust  sprayers,"  "sulfuring 
machines,"  etc. 

There  are  several  hand  "dust  sprayers"  of  American  manufacture 
which  were  originally  designed  for  the  distribution  of  paris  green. 
The  current  of  air  by  which  the  powder  is  blown  on  to  the  plant  is  pro- 
duced by  a  rotary  fan.  The  powder  is  stirred  by  various  devices  in 
the  different  machines  and  blown  out  of  a  reservoir  through  a  tin  or 
rubber  tube. 

The  machines  made  in  Europe  specially  for  the  distribution  of 
sulfur  differ  from  the  above  principally  in  the  method  of  producing 
the  current  of  air.  This  is  produced  by  a  valve  bellows  similar  in  prin- 
ciple to  the  old-fashioned  blacksmith's  bellows. 

All  the  available  American  machines  and  one  of  the  best  European 
machines  were  tested  this  year  by  the  Experiment  Station.  None  of 
the  American  machines  was  found  suitable  for  the  purpose.  They  were 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE. 


Fig.  9.     Various  forms  of  Hand  Sulfur  Distributers. 

«,  Upper  left  hand,  European  machine.     &,  Upper  right  hand,  sulfur  bellows,     c 
and  d,  Lower  figures,  American  machines. 

nearly  all  extremely  cumbersome  and  wasteful  of  sulfur.  The  best  of 
those  tested  is  shown  by  the  photograph  of  fig.  9,  d.  They  all  have 
several  very  serious  defects  for  the  purpose  tested.  The  regulation  of 
the  flow  of  sulfur  is  very  imperfect  and  it  is  necessary  to  use  an  unnec- 


336  UNIVERSITY  OF  CALIFORNIA— EXPERIMENT  STATION. 

essarily  large  quantity  in  order  to  cover  the  whole  vine.  This  is  espe- 
cially true  in  the  case  of  high  vines.  The  machines  worked  fairly  well 
only  when  the  outlet  tube  was  held  in  a  downward  direction.  While 
treating  the  tops  of  high  vines  the  sulfur  accumulates  in  the  tube, 
which  finally  chokes  up.  In  order  to  clear  the  tube  it  is  necessary  to 
hold  it  down,  upon  which  the  accumulated  sulfur  runs  out  and  is 
wasted  on  the  ground. 

The  European  machine,  on  the  contrary,  gave  most  excellent  results. 
(See  fig.  9, a.)  The  regulation  device  enables  the  operator  to  govern 
the  amount  of  sulfur  blown  out  with  great  precision.  This  is  a  very 


Fig.  10.     Sulfur  cloud  to  cover  the  whole  vine. 

important  point,  as  it  makes  it  possible  to  use  various  grades  of  sulfur 
effectively  and  economically.  The  reservoir  of  the  machine  holds 
enough  sulfur  to  treat  two  or  three  acres  without  refilling,  but  is  less 
fatiguing  to  carry  than  the  other  machines,  which  hold  only  one- 
quarter  as  much.  The  sulfur  is  blown  out  in  a  fine  impalpable  powder 
(see  figs.  10,  11,  and  12),  and  owing  to  the  form  of  the  machine  it  can 
be  applied  to  any  part  of  the  vine.  By  standing  a  little  distance  from 
the  vine  a  single  puff  can  be  made  to  distribute  the  sulfur  over  the 
whole  exterior  of  the  vine.  (See  fig.  10.)  Then  after  poking  the  end 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE.  337 

of  the  tube  into  the  center  of  the  vine  another  puff  will  thoroughly 
sulfur  the  interior.  (See  fig.  11.)  By  a  small  attachment  placed  on 
the  end  of  the  tube  the  cloud  may  be  forced  upwards  and  the  under 
side  of  the  leaves  more  thoroughly  treated  (see  fig.  12),  but  this  is 
seldom  necessary.  The  work  is  much  less  laborious  than  with  any  of 
the  other  methods  tried  and  the  workman  is  less  liable  to  be  troubled 
by  the  sulfur  getting  into  his  eyes. 


Fig.  11.     Sulfuring  interior  of  the  vine. 


Fig.  12.     Sulfuring  the  under  side  of  leaves. 

A  machine  made  in  San  Francisco  on  the  plan  of  the  European 
machines  was  found  excellent  in  all  respects  except  that  it  lacked  the 
regulating  device. 

The  following  table  shows  some  of  the  results  obtained  with  the 
various  methods  of  sulfuring : 


338  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION. 

SULFUE  AND  TIME  TAKEN  TO  SULFUK  500  VINES  (1  ACKE). 

Mot^nri         2  year  old  Vines  3  year  old  Vines                              4  year  old  Vines 

Ibs.  ofS.     time:  min.  Ibs.  of  S.     time:  min.                  Ibs.  of  &.    time:  min. 

A  4.82  30  8.4  56 

B            8.61             30  11.1               63 

C            6.56             33  12.7               56 

D            9.84             30  23.9               65 

E            9.43             33  28.6               60 

F            6.56             33  28.9               58 

G          12.30             30  42.8               69 

A.  European  knapsack  bellows.  (Fig.  9,  a.) 

B.  San  Francisco  knapsack  bellows. 

C.  Hand  bellows.     (Fig.  9,  6.) 

I).  American  dust  sprayer  (the  best  of  those  tested).     (Fig.  9,  d.) 

E.  Sulfur  sack. 

F.  Perforated  can. 

G.  Hand  distribution. 

Each  of  the  results  given  in  the  above  table  is  the  average  of  four 
tests  made  by  four  men  and  may  be  accepted  as  accurate  so  far  as  the 
amounts  of  sulfur  are  concerned.  The  time  given  for  sulfuring,  how- 
ever, is  less  accurate.  The  four  men  doing  the  sulfuring  worked  to- 
gether with  different  machines,  so  there  \vas  a  tendency  for  the  man 
with  the  most  laborious  machine  to  work  harder  to  keep  up  with  the 
others.  This  makes  the  difference  in  time  between  the  various  methods 
less  than  it  would  be  in  practice.  No  account,  moreover,  was  taken  of 
the  time  needed  to  go  for  sulfur  and  to  fill  the  machines.  This  would 
still  further  increase  the  differences  in  time. 

In  all  the  tests  made,  the  vines  were  given  as  complete  a  sulfuring 
as  was  possible  with  the  means  employed.  A  fair  sample  of  sublimed 
sulfur  was  used. 

ESTIMATE  OF  COST  OF  SULFUKING  500  MATURE  VINES. 
Method 


1st  S. 
Ibs. 
line  5.0 
7.0 

2nd  S. 
Ibs. 

7.5 
13.0 
20.0 
30.0 

3rd  S. 
Ibs. 
10.0 
20.0 
30.0 
50.0 

Total 
S.  Ibs. 
22.5* 

40.0f 

eo.ot 

87.0f 

Cost       Labor  at 
of  S.      $2  per  day 
.56           .60* 
.80         .60 
$1.20         .60 
1.74         .60 

Total 
cost 
$1.16 
1.40 
1.80 
2.34 

10.0 
L    7.0 

Hand  bellows 

Dust    sprayer 

Perforated  can 

Hand  distribution  ..     ..  12.0         40.0         75.0       127.0f  3.54         .60  4.14 


*  Sulfur  of  good  quality  at  $2.50  per  100  Ibs. 

t  Sulfur  of  medium  quality  at  $2  per  100  Ibs. 

j  The  time  required  will  vary  from  three-quarters  of  an  hour  to  one  and  one- 
half  hours  per  acre  (500  vines),  according  to  the  size  of  the  vines  and  the  method 
used.  An  average  of  one  acre  an  hour  is  taken  for  the  three  sulfurings  for  all  the 
machines.  In  practice  it  would  probably  be  less  than  this  for  the  best  machines 
and  more  for  the  inferior  methods. 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE.  339 

The  above  estimates  are  based  on  the  tests  made, — tests  which 
proved  effective  in  completely  controlling  the  disease.  The  amounts 
indicated  for  an  acre  when  the  European  machine  is  used  are  less  than 
is  recommended  by  the  best  authorities  in  the  south  of  France.  Viala 
in  ' '  Les  Maladies  de  la  Vigne ' '  gives  15-30-40  kilos  as  the  amounts  to 
be  used  for  the  three  sulfurings  of  an  hectare.  This  corresponds  to 
about  75  pounds  to  the  acre.  The  vines  in  the  south  of  France,  how- 
ever, are  planted  much  closer  than  ours,  usually  about  1,800  to  the 
acre.  The  amount  for  500  vines  therefore  would  be  a  little  less  than 
our  tests  indicate. 

Cost  of  Treatment.  The  total  cost  for  sulfur  ing,  including  mate- 
rial and  labor,  will  vary,  if  the  best  hand  machine  is  used,  from  about 
50  cents  per  acre  for  one  treatment  in  the  interior  to  $1.25  for  three 
treatments  in  the  coast  valleys,  or  $2  to  $2.25  for  five  treatments  in  the 
most  affected  localities. 

Power  and  Traction  Machines.  No  machines  of  this  description 
have  been  tested  by  the  Experiment  Station  for  the  sulfuring  of  vines. 
In  Europe  it  is  only  lately  that  they  have  been  used  at  all.  The  diffi- 
culties attending  the  distribution  of  large  quantities  of  sulfur  in  a  fine 
cloud  by  means  of  a  current  of  air  are  very  great.  It  is  claimed  by  the 
manufacturers  of  several  machines  that  these  difficulties  have  been 
overcome,  but  the  machines  are  very  costly. 

Moreover,  it  is  hard  to  conceive  of  a  machine  which  would  do  the 
work  effectively  without  wasting  a  large  part  of  the  sulfur.  When  the 
vines  are  small,  if  the  sulfur  were  thrown  over  a  large  area,  as  much 
would  go  on  the  ground  as  on  the  vines.  As  the  vines  when  they  first 
start  cover  only  from  5  per  cent,  to  10  per  cent,  of  the  area,  the  amount 
of  sulfur  used  by  the  power  machine  would  be  from  ten  to  twenty  times 
times  as  much  as  is  necessary.  As  the  cost  of  sulfur  and  of  labor  are 
epproximately  equal  with  the  best  knapsack  machine,  no  saving  in  cost 
of  labor  would  offset  this  waste  of  sulfur. 

When  the  vines  are  large  it  is  doubtful  whether  any  machine  could 
throw  the  sulfur  as  effectively  into  the  interior  of  the  vine  where  it  is 
most  needed  as  can  be  done  with  the  tube  of  a  knapsack  machine. 

There  is  one  consideration  which  makes  it  seem  possible,  however, 
that  an  effective  power  machine  might  have  its  uses  here.  There  is 
nothing  more  expensive  than  losing  the  crop,  and  a  power  machine 
might  make  it  possible  to  sulfur  a  vineyard  and  save  the  crop  when  it 
was  impossible  to  have  the  work  done  by  hand.  Even  at  an  extra  cost 
of  several  dollars  per  acre  this  of  course  would  be  an  advantage. 

Quality  of  Sulfur.    Any  kind  of  sulfur  in  the  condition  of  a  pow- 


340 


UNIVERSITY   OF  CALIFORNIA— EXPERIMENT  STATION. 


der  will  control  the  disease  if  used  as  directed.  Coarse  powders,  how- 
ever, must  be  used  in  much  greater  quantities  and  are  more  difficult  to 
apply  properly.  The  absolute  purity  of  the  sulfur  is  of  little  impor- 
tance, provided  there  is  no  large  adulteration  with  inert  and  useless 
substances  such  as  gypsum. 

Many  samples  of  sulfur  were  received  at  the  Experiment  Station 
during  the  past  year  and  examined.  Most  of  these  samples  were  sent 
by  grape  growers.  They  were  all  found  to  be  practically  pure  and 
unmixed.  In  the  important  matter  of  fineness,  however,  they  differed 
widely.  Two  or  three  of  them  were  so  coarse  as  to  be  almost  valueless 
for  sulfuring  vines.  (See  fig.  16,  Sulfur  No.  8.)  A  few  were  very  good 
and  most  of  them  were  passable.  The  prices  quoted  by  the  senders 
were  little  indication  of  the  value  of  the  samples.  Some  of  the  cheapest 
were  of  excellent  quality  for  the  purpose  (see  fig.  15,  Sulfur  No.  16), 
and  some  of  the  most  expensive  were  among  the  worst  (see  fig.  16, 
Sulfur  No.  8).  This  shows  the  need  of  a  careful  examination  before 
purchasing. 

Some  of  the  results  of  our  examinations  are  shown  in  the  following 
table : 

SAMPLES  OF  SULFUE  KECEIVED  AND  EXAMINED  BY  THE   STATION 

IN  1906. 


No. 
30 

Oy 

3 

20 
19 
28 
26 
15 
24 

6 

29 
13 
18 

4 
16 
31 
23 
25 
10 
17 

5 
21 
27 
12 

1 

7 

2 

11 
14 

8 


Price 

C 

66.8 

60.8 

$52.50 

60.0 

45.00 

58.8 

70.00 

52.0 

41.00 

50.8 

50.0 

49.2 

43.00 

48.0 

55.00 

47.6 

60.00 

46.0 

44.00 

45.6 

42.8 

55.00 

40.0 

32.00 

51.6 

46.8 

46.0 

45.00 

46.0 

30.00 

45.6 

45.6 

40.00 

45.2 

45.00 

45.0 

30.00 

44.5 

39.6 

44.00 

37.6 

45.00 

37.6 

47.50 

37.2 

36.0 

34.4 

47.50 

34.0 

Sublimed,  very  fine,  no  coarse  material. 

Sublimed,  very  good,  very  little  coarse  material. 

Sublimed,  very  good,  some  coarse  material. 

Sublimed,  very  good,  some  coarse  material. 

Sublimed,  good,  but  with  many  large  grains. 

Sublimed,  good,  but  with  considerable  coarse  material. 

Sublimed,  good,  but  with  considerable  coarse  material. 

Sublimed,  good,  but  with  some  coarse  material. 

Sublimed,  fair,  about  one-third  of  coarse  material. 

Sublimed,  fair,  but  some  coarse  angular  material. 

Sublimed,  fair,  with  considerable  coarse  material. 

Sublimed,  fair,  with  considerable  coarse  material. 

Sublimed,  with  much  medium  coarse  material. 

Sublimed,  with  much  coarse  material. 

Ground,  good,  with  little  coarse  material. 

Ground,  good,  with  about  one-third  coarse  material. 

Ground,  good,  with  about  one-third  medium  material. 

Ground,  fair,  about  one-half  fine  material. 

Ground,  good,  except  for  some  large  particles. 

Ground,  good,  but  considerable  coarse  material. 

Ground. 

Ground,  fair,  about  one-half  fine  material. 

Ground,  fair,  about  one-half  fine  material. 

Ground,  much  coarse  material. 

Ground,  much  coarse  material. 

Ground,  fair,  much  coarse  material. 

Ground,  coarse. 

Ground,  poor,  very  little  fine  material. 

Ground,  very  poor,  hardly  any  fine  material. 

Ground,  principally  large  particles. 


OTDIUM  OR  POWDERY  MILDEW  OF  THE  VINE. 


341 


Fig.  13.     Sublimed  Sulfur  of  very  good  quality.     Sulfur  No.  30. 


Fig.  14.     Sublimed  Sulfur  of  poor  quality.     Sulfur  No.  4. 


342  UNIVERSITY  OF  CALIFORNIA— EXPERIMENT  STATION. 


Fig.  15.     Ground  Sulfur  of  good  quality.     Sulfur  No.  16. 


Fig.  16.     Ground  Sulfur  of  very  bad  quality.     Sulfur  No.  8, 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE.  343 

The  data  given  are  the  prices  and  the  results  of  the  Chancel  test, 
column  C,  and  of  the  microscopical  examination.  The  Chancel  test  is 
the  determination  of  the  amount  of  settling  that  occurs  when  5  grams 
of  sulfur  are  allowed  to  stand  in  a  cylinder  after  shaking  up  with  25 
cubic  centimeters  of  ether.  The  number  represents  the  percentage  of 
the  height  of  the  cylinder  occupied  by  the  sulfur  after  settling.  It  is 
a  very  convenient  and  quick  method  of  testing  the  fineness  of  the  sul- 
fur. (See  fig.  17.) 


30  28  4  16  8 

FIG.  17.      Comparative  volumes  of  5  grams  of  different  sulfurs. 

No.  30.     Sublimed  Sulfur,  Chancel  No.  66.8  $70.00 

No.  28.     Sublimed  Sulfur,  Chancel  No.  50.8  ...  41.00 

No.     4.     Sublimed  Sulfur,  Chancel  No.  40.0  55.00 

No.  16.     Ground  Sulfur,  Chancel  No.  51.6    32.00 

No.     8.     Ground  Sulfur,  Chancel  No.  38.0    47.50 

The  numbers  corresponding  to  good  commercial  sublimed  sulfur 
are  50  to  70 ;  those  of  the  finest  quality  show  75  to  90.     Powdered  or 


344  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION. 

ground  sulfur  of  the  best  quality  will  show  from  60  to  70,  and  those  of 
ordinary  quality  43. 1 

All  the  sulfurs  examined,  with  the  exception  of  two  of  the  ground 
samples  (Nos.  8  and  14),  contained  sufficient  fine  material  to  do  effec- 
tive work,  but  the  amount  it  would  be  necessary  to  use  of  the  various 
grades  would  vary  considerably.  If  the  sulfur  is  applied  by  hand  or 
with  perforated  cans,  any  of  the  sulfurs  except  Nos.  14  and  8  would 
probably  be  nearly  equally  good,  and  therefore  the  cheapest  would  be 
best.  If  we  use  several  times  as  much  as  is  needed,  as  wre  must  \vith 
these  methods,  it  matters  little  if  25  per  cent,  or  50  per  cent,  of  the 
sulfur  is  useless. 

When  using  an  effective  sulfur  machine  it  is  possible  to  utilize  the 
superior^  of  the  finer  grades,  and  in  this  case  it  is  undoubtedly  ad- 
visable to  use  the  better  qualities.  (See  figs.  13  and  15.) 

A  few  simple  directions  for  the  examination  of  sulfur  may  be  of 
use  to  the  grower. 

1.  The  finer  the  sulfur  the  more  bulky.     Therefore  if  several  sul- 
furs are  in  sacks  of  equal  weight,  the  largest  sack  will  contain  the 
finest  sulfur.    A  110-pound  sack  of  good  flowrers  of  sulfur  is  twice  as 
large  as  a  110-pound  sack  of  very  coarse  ground.     The  difference  in 
bulk  between  equal  weights  of  sulfurs  of  various  qualities  is  shown  in 
fig.  17,  representing  the  Chancel  test. 

2.  The  color  of  sublimed  sulfur  is  a  clear,  bright  yellow.     The 
color  of  ground  sulfur  will  vary  with  the  fineness.     Coarsely  ground 
sulfur  is  almost  of  the  same  color  as  sublimed.     When  finely  ground, 
the  color  becomes  whitish.    The  whiter  a  ground  sulfur,  the  finer  it  is. 
provided  the  color  is  not  due  to  adulterants. 

3.  A  good  sublimed  sulfur  should  feel  as  soft  as  flour  when  rubbed 
with  the  fingers  in  the  palm  of  the  hand.     If  hard  particles  are  felt, 
the  sulfur  is  not  of  the  best  quality.     Ground  sulfur  always  feels  a 
little  gritty,  but  the  hard  particles  should  not  be  large  or  numerous. 

4.  A  very  good  idea  of  the  fineness  of  a  sulfur  can  be  obtained  by 
the  use  of  an  ordinary  good  hand  magnifying  glass  costing  about  $1. 
A  magnification  of  10  or  20  diameters  is  sufficient.    With  a  little  expe- 
rience sublimed  and  ground  sulfur  can  be  distinguished  by  this  means. 
The  particles  of  sublimed  sulfur  are  all  nearly  spherical  with  smooth 
outlines.    Those  of  ground  sulfur  are  irregular  and  with  sharp  edges. 

The  sulfur  is  most  easily  examined  when  spread  on  a  piece  of  glass 
over  a  dark  background.  A  good  way  to  spread  the  sulfur  is  to  place 


Yiala,  P.,  Les  Maladies  de  la  Vigne,  p.  53. 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE.  345 

a  small  pinch  on  the  glass,  wet  it  with  a  few  drops  of  ether,  and  shake. 
This  will  distribute  the  sulfur  in  a  thin  layer  over  the  glass  and  much 
facilitate  the  examination. 

5.  A  test  of  the  purity  may  be  made  by  burning  a  pinch  of  the 
sulfur  on  a  piece  of  white  porcelain — a  broken  plate,  for  example.  To 
make  the  burning  complete,  hold  the  piece  of  plate  over  a  lamp  or  on 
top  of  a  very  hot  stove.  A  pure  sulfur  burns  away  completely,  leaving 
only  a  black  stain  on  the  plate.  Any  dust  or  particles  that  are  left 
indicate  adulteration. 

The  fine  sulfurs  are  superior  in  three  important  respects:  (1) 
They  capable  of  more  perfect  distribution;  (2)  they  offer  a  larger 
surface  to  the  air  and  therefore  give  off  more  fumes;  (3)  they  adhere 
better  to  the  leaves. 

A  pound  of  a  very  fine  sublimed  sulfur  such  as  No.  30  (see  fig.  13), 
the  particles  of  which  measure  .01  mm.  in  diameter,  if  evenly  distrib- 
uted and  none  lost,  would  give  about  15,000  particles  for  every  square 
inch  of  leaf  and  cane  surface  on  an  acre  of  large  vines.  A  pound  of  a 
very  coarse  sulfur  such  as  No.  8  (see  fig.  16),  the  particles  of  which 
have  twenty-five  times  as  large  a  diameter,  would  supply  only  about 
one  particle  for  every  square  inch.  Moreover,  a  much  larger  propor- 
tion of  the  coarse  sulfur  would  be  lost  by  failing  to  adhere  to  the  leaves 
and  falling  on  the  ground.  Perhaps  the  most  important  advantage  of 
the  finest  sulfur  in  this  respect  is  that  the  impalpable  powder  floats  so 
lightly  in  the  air  that  it  reaches  and  adheres  to  the  lower  surfaces  of 
the  leaves  and  canes.  A  finely  powdered  sulfur  such  as  No.  16  (see 
fig.  15)  would  probably  be  just  as  effective  as  the  sublimed,  for  though 
it  contains  a  certain  proportion  of  coarser  particles,  the  finer  material 
has  not  the  tendency  to  cohere  in  the  groups  of  particles  characteristic 
of  sublimed  sulfur. 

The  quantity  of  fumes  given  off  by  a  sulfur  must  be  about  in  the 
proportion  of  the  extent  of  surface  which  the  particles  present  to  the 
air.  This  surface  is  inversely  proportionate  to  the  diameter  of  the  par- 
ticles. A  pound  of  sulfur,  No.  30  or  No.  16,  would  possess  a  surface 
twenty-five  times  as  great  as  that  of  No.  14,  and  would  therefore  give 
off  fumes  much  more  rapidly  and  in  greater  quantity. 

OTHEE  METHODS  OF  TREATMENT. 

Combined  Treatments.  Various  other  substances  and  sprays  have 
been  suggested  and  tried  for  the  control  of  the  Oidium  during  the 
growing  season.  There  are  two  cases  in  which  it  has  seemed  desirable 
to  attempt  to  find  another  method  of  control.  One  of  these  is  where  it 


346  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

is  necessary  to  treat  for  another  vine  disease  which  cannot  be  con- 
trolled by  sulfur  at  the  same  time.  In  Europe,  where  spraying  with 
copper  solutions  is  necessary  to  protect  the  vines  from  Peronospora, 
Black  Rot,  and  Botrytis,  various  sprays  have  been  tried  with  the  object 
of  controlling  the  Oidium  at  the  same  time.  These  sprays  are  princi- 
pally liquids  containing  Bordeaux  mixture,  copper  sulfate,  or  sulfoste- 
atite  together  with  "wetable"  sulfur.  There  is  considerable  uncer- 
tainty as  to  the  success  of  these  combinations,  and  as  the  diseases  they 
are  intended  to  reach  do  not  exist  in  California  they  are  of  little  in- 
terest to  us. 

The  other  case  is  where  sulfur  has  been  found  ineffective  or  too 
slow  in  its  action.  This  seems  to  be  the  case  in  the  Eastern  States,  and 
may  be  in  certain  parts  of  the  coast  region  of  California  or  perhaps 
exceptionally  in  other  regions  in  abnormal  years. 

Liquid  Sprays.  Dry  sulfur  to  be  effective  requires  warm  weather. 
If  the  weather  is  cool  its  action  is  slow  or  nil.  Certain  sprays  act  im- 
mediately on  the  Oidium  whatever  the  temperature.  It  should  be  re- 
membered, however,  that  the  Oidium  grows  very  slowly  or  not  at  all 
below  temperatures  at  which  sulfur  is  effective.  Cases,  however,  may 
arise  where,  through  neglect  of  proper  sulfuring,  the  vines  may  be 
badly  attacked  by  mildew,  and  owing  to  the  coolness  of  the  weather 
when  the  trouble  is  first  perceived  sulfur  may  act  too  slowly.  In  such 
cases  it  may  be  advisable  to  use  a  quick  acting  spray. 

Such  a  condition  might  occur  in  a  cool  late  spring. 

Another  case  in  which  a  spray  may  be  useful  is  where  the  vines 
have  been  very  badly  affected  the  previous  autumn  and  the  canes  are 
covered  with  winter  spores  and  perhaps  hibernating  mycelium  ready 
to  infect  the  new  shoots  on  the  first  warm  day.  A  spraying  just  as  the 
buds  swell  might  be  of  help  in  such  a  case.1 

Spraying  in  the  summer  should  never  be  necessary,  as  the  heat  is 
sufficient  to  cause  the  sulfur  to  act  quickly.  It  has  been  suggested  that 
late  sulfuring  is  inadvisable  because  it  may  cause  spotting  of  the 
grapes.  If  the  grapes  have  not  commenced  to  ripen  this  will  not  occur 
if  the  sulfur  is  applied  properly,  and  if  they  have  commenced  to  ripen 
they  are  safe  from  the  disease,  and  sulfuring  to  protect  the  vines  should 
be  deferred  until  the  grapes  are  gathered. 

No  sprays,  however,  do  the  work  as  thoroughly  as  sulfur.  A  spray 
only  kills  the  fungus  which  it  actually  touches,  and  the  most  perfect 
spraying  possible  will  leave  some  parts  of  the  vine  untouched.  Where 


1  Tests  of  winter  spraying  by  Pacottet  and  Eavaz  in  France  gave  no  favorable 
results. 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE.  347 

a  spray  is  used  it  should  therefore  be  followed  by  an  application  of  dry 
sulfur  to  complete  the  work. 

The  sprays  which  have  been  found  most  effective  for  this  purpose 
are  Bordeaux  mixture,  permanganate  of  potash,  and  alkaline  polysul- 
fids.  Vines  are  not  easily  injured  by  copper  salts,  so  that  a  strong 
Bordeaux  can  be  used.  The  6-4-50  formula  would  be  suitable. 

Permanganate  of  potash  at  the  rate  of  one  pound  to  100  gallons  of 
water  has  been  found  effective.  A  little  chloride  of  potash  or  common 
salt  improves  the  spray  by  increasing  its  adhesive  qualities. 

Liver  of  sulfur  at  the  rate  of  4  pounds  to  100  gallons  of  water  with 
4  pounds  of  soap  has  also  been  used  with  success.  Alkaline  polysulfids 
have  also  been  used  effectively  in  the  same  way.  These  sprays  are  more 
permanent  in  their  effects  than  the  copper  and  permanganate  mixtures 
because  a  small  amount  of  finely  divided  free  sulfur  is  set  free,  which 
acts  in  the  same  way  as  the  powdered  sulfur  when  applied  in  the  usual 
way.  It  is  very  probable  that  a  weak  lime-salt-sulfur  spray  such  as  is 
in  common  use  on  fruit  trees  would  be  equally  effective. 

WINTER  TREATMENT. 

As  the  fungus  passes  the  winter,  when  it  has  no  green  leaves  to 
grow  on,  in  the  form  of  resting  spores  on  the  canes  and  in  the  soil  and 
perhaps  of  resting  mycelium  under  the  bud  scales,  it  has  been  sug- 
gested that  a  winter  treatment  which  would  destroy  these  hibernating 
forms  would  be  the  best  method  of  control,  or  at  least  that  it  would 
much  simplify  the  summer  treatment. 

The  methods  usually  proposed  are  to  spray  the  vines  after  pruning 
with  the  lime-salt-sulfur  used  for  fruit  trees  or  with  a  2  per  cent,  solu- 
tion of  bluestone.  Others  advise  swabbing  the  vines  at  the  same  time 
with  a  saturated  solution  of  iron  sulfate  (copperas)  acidified  with  1 
per  cent  .of  sulfuric  acid.  To  make  the  treatment  more  thorough,  some 
remove  all  the  dry  bark  of  the  vine  by  means  of  scrapers  before  treat- 
ment. This  is  supposed  to  destroy  all  the  perithecia  on  the  vine.  In 
order  to  prevent  infection  from  the  hibernating  mycelium  under  the 
bud  scales  it  is  further  advised  to  spray  the  vines  with  Bordeaux  mix- 
ture just  as  the  buds  swell  in  the  spring. 

Such  treatments  as  these  are  of  course  very  expensive  and  cost 
more  than  several  sulfurings,  so  that,  unless  they  can  be  proved  to  be 
effective,  they  should  not  be  adopted.  There  is  considerable  evidence 
that  such  treatment  makes  the  vines  more  vigorous  and  healthy,  but 
that  it  has  any  effect  on  controlling  the  Oidium  is  doubtful.  It  seems 
unnecessary,  because  if  we  control  the  Oidium  in  the  summer,  as  we 


348  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION. 

must  do  to  save  our  crop  entirely,  there  will  be  no  winter  spores  formed 
and,  therefore,  no  use  in  spraying  for  them. 

Winter  treatment,  moreover,  cannot  be  completely  effective  because, 
however  well  done,  it  cannot  destroy  all  the  resting  spores,  because 
most  of  them  are  in  the  soil,  and  if  but  a  few  escape,  they  are  capable 
of  infecting  the  whole  vineyard  when  the  weather  conditions  are  favor- 
able. Sulfuring,  therefore,  is  necessary  even  when  winter  spraying  is 
practised. 

There  is  reason  to  believe,  moreover,  that  winter  treatment  is  com- 
pletely ineffective.  Every  other  vine  in  a  small  patch  of  vines  at 
Berkeley  was  treated  last  winter  with  bluestone,  iron  sulfate,  or  Bor- 
deaux mixture.  In  the  spring  just  as  much  mildew  was  found,  on  its 
first  appearance,  on  the  treated  as  on  the  untreated  vines. 

A  still  more  convincing  experiment  is  described  in  the  "Revue  de 
Viticulture,"  No.  655,  page  12.  This  seems  to  prove  as  well  as  a  single 
experiment  can :  First,  that  the  fungus  does  not  pass  the  winter  to 
any  extent  in  the  summer  form  under  the  bud  scales ;  and  second,  that 
the  most  thorough  winter  treatment  is  useless  if  no  winter  spores  are 
formed,  and  completely  ineffective  if  they  are. 

Mr.  Pacottet  says  in  the  article  quoted :  "In  1904  we  observed  that 
the  spring  attack  of  Oidium  occurred  first  precisely  in  those  hothouses 
of  Nanterre  where  perithecia  had  been  found  in  the  autumn  of  the  pre- 
vious year.  The  same  fact  was  observed  in  1905.  This  led  us  to  make 
careful  observations  the  following  year  on  the  manner  and  time  of  the 
appearance  of  the  Oidium. 

"Oidium  appeared  at  the  end  of  March,  1906,  and  only  in  those 
grape  houses,  to  the  number  of  20,  where  the  presence  of  winter  spores 
had  been  noted  in  November  of  the  previous  year.  In  these  houses  the 
fungus  appeared  with  such  intensity  that  nearly  every  leaf  showed 
simultaneously  several  patches. 

"These  observations  acquire  especial  importance  when  considered 
in  connection  with  the  various  hypotheses  which  have  been  advanced 
regarding  the  modes  in  which  the  Oidium  passes  the  winter,  especially 
as  regards  the  hibernating  of  fragments  of  mycelium  (summer  form) 
adhering  to  the  canes  and  capable  of  vegetating  anew  in  the  spring. 

"At  Nanterre  the  disinfection  of  the  vines  is  as  complete  as  it  is 
possible  to  make  it.  After  removing  the  old  bark  they  are  treated  with 
boiling  water  and  swabbed  with  a  30  per  cent,  solution  of  iron  sulfate. 
They  are  then  covered  with  a  paste  of  lime  and  sulfur.  *  *  *  Be- 
fore the  starting  of  the  buds,  the  walls,  glass,  and  casings  are  disin- 
fected with  strong  washes  and  the  air  with  the  fumes  of  burning 
sulfur." 


OIDIUM  OR  POWDERY  MILDEW  OF  THE  VINE.  349 

Now,  even  with  such  thorough  winter  treatment  as  this,  which  it 
would  be  quite  impracticable  to  apply  in  a  vineyard,  no  apparent  effect 
was  obtained  in  the  control  of  the  spring  infection.  The  spring  infec- 
tion was  due,  therefore,  to  spores  which  were  not  on  any  part  of  the 
vine,  and  from  which  no  kind  of  spraying  or  swabbing  of  the  vine 
would  be  any  protection  whatever. 

Pacottet  concludes,  therefore,  that  practically  all  the  spring  infec- 
tion is  due  to  spores  which  have  passed  the  winter  in  the  soil.  These 
are  the  spores  contained  in  the  perithecia  which  have  dropped  in  the 
autumn  with  the  leaves  on  which  they  are  formed.  His  advice  for  hot- 
house treatment  is  to  gather  all  these  leaves  before  they  fall  and  to  burn 
them. 

This  again  is  impracticable  in  a  vineyard,  and  we  are  forced  again 
to  the  conclusion  that  no  form  of  winter  treatment  is  of  any  use  in  the 
control  of  Oidium  in  vineyards,  and  that  the  only  practicable  method 
is  proper  sulfuring  of  the  vines  in  spring  and  summer.  This  will' pre- 
vent injury  to  the  vines,  and  if  thorough  will  prevent  the  formation  of 
winter  spores. 


SUMMAEY. 

Oidium  is  one  of  the  most  serious  diseases  of  the  vine  and  the  only 
serious  fungus  disease  of  vines  in  California. 

It  is  capable  of  destroying  the  whole  crop  in  most  vineyards  in  bad 
seasons  if  not  controlled. 

Much  more  damage  is  done  to  vines  and  grapes  in  California  than 
is  usually  supposed,  but  the  control  is  much  easier  and  more  certain 
than  in  most  vine-growing  countries. 

The  disease  attacks  leaves,  canes,  and  fruit  during  the  growing 
season. 

It  grows  only  on  the  exterior  green  surfaces  of  the  vine  and  passes 
the  winter  in  the  form  of  resting  spores  in  the  soil. 

Certain  varieties  of  vines  are  very  susceptible  and  others  compara- 
tively resistant. 

Moist  warm  atmosphere  favors  the  growth  of  the  fungus. 

Methods  of  training,  cultivation,  and  irrigation  which  keep  the  vine 
dry  by  thorough  aeration  minimize  the  danger  of  attack. 

Dusting  the  vines  with  sulfur  is  the  cheapest  and  most  efficient 
method  of  control  in  California. 

The  weather  and  the  season  when  the  sulfur  is  applied  are  of  great 
importance. 


350  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

The  number  of  treatments  will  differ  with  the  locality,  the  season, 
and  the  variety  of  vine. 

Vines  should  be  protected  from  late  attacks  even  after  the  grapes 
are  gathered. 

Young  vines  should  be  protected  as  much  as  old,  even  when  they 
are  in  the  nursery. 

The  usual  methods  of  applying  sulfur  by  hand  or  with  perforated 
cans  is  wasteful  and  uncertain. 

A  good  sulfur  sprayer  is  essential  for  the  best  results.  None  of  the 
American  dust  sprayers  tried  is  suitable  for  the  purpose.  The  "Ver- 
morel  souf reuse  Torpille ' '  was  found  to  answer  perfectly. 

The  cost  of  treatment,  when  a  good  sulfur  distributer  is  used,  va- 
ries from  50  cents  to  $2.25  per  acre,  according  to  the  number  of  treat- 
ments necessary.  The  cost  is  about  equally  divided  between  sulfur 
and  labor. 

Traction  machines  do  not  promise  any  improvement  in  cost  or 
efficiency. 

Finely  divided  sublimed  or  powdered  sulfur  should  be  used. 
Coarse  sulfurs  cost  more  because  more  is  needed  and  they  are  less 
effective. 

No  other  form  of  summer  treatment  is  so  effective  as  sulfuring,  but 
in  rare,  special  cases  a  supplementary  spray  may  be  useful. 

Winter  treatment  is  in  all  probability  of  no  use  in  the  control  of 
Oidium. 


OIDIUM  OB  POWDERY  MILDEW  OF  THE  VINE.  351 


STATION  PUBLICATIONS  AVAILABLE  FOR  DISTRIBUTION. 


REPORTS. 

1896.  Report  of  the  Viticultural  Work  during  the  seasons  1887-93,  with  data  re- 

garding the  Vintages  of  1894-95. 

1897.  Resistant  Vines,  their  Selection,  Adaptation,  and  Grafting.     Appendix  to 

Viticultural  Report  for  1896. 

1898.  Partial  Report  of  Work  of  Agricultural  Experiment  Station  for  the  years 

1895-96  and  1896-97. 
1900.     Report  of  the  Agricultural  Experiment  Station  for  the  year  1897-98. 

1902.  Report  of  the  Agricultural  Experiment  Station  for  1898-1901. 

1903.  Report  of  the  Agricultural  Experiment  Station  for  1901-03. 

1904.  Twenty-second  Report  of  the  Agricultural  Experiment  Station  for  1903-04. 

TECHNICAL  BULLETINS--ENTOMOLOGICAL  SERIES. 

Vol.  1,  No.  1.     Wing  Veins  of  Insects. 

No.  2.     Catalogue  of  the  Ephydridae. 

BULLETINS. 

Eeprint.  Endurance  of  Drought  in  Soils  of  the  Arid  Region. 

No.  128.  Nature,  Value,  and  Utilization  of  Alkali  Lands,  and  Tolerance  of  Alkali. 

(Revised  and  Reprint,  1905.) 

133.  Tolerance  of  Alkali  by  Various  Cultures. 

140.  Lands  of  the  Colorado  Delta  in  Salton  Basin,  and  Supplement. 

141.  Deciduous  Fruits  at  Paso  Robles. 

142.  Grasshoppers  in  California. 
144.  The  Peach-Worm. 

147.  Culture  Work  of  the  Sub-stations. 

148.  Resistant  Vines  and  their  Hybrids. 

149.  California  Sugar  Industry. 

150.  The  Value  of  Oak  Leaves  for  Forage. 

151.  Arsenical  Insecticides. 

152.  Fumigation  Dosage. 

153.  Spraying  with  Distillates. 

154.  Sulfur  Sprays  for  Red  Spider. 
156.  Fowl  Cholera. 

158.  California  Olive  Oil;  its  Manufacture. 

159.  Contribution  to  the  Study  of  Fermentation. 

160.  The  Hop  Aphis. 

161.  Tuberculosis  in  Fowls.     (Reprint.) 

162.  Commercial  Fertilizers.     (Dec.  1,  1904.) 

163.  Pear  Scab. 


352  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

164.  Poultry  Feeding  and  Proprietary  Foods.     (Reprint.) 

165.  Asparagus  and  Asparagus  Bust  in  California. 

166.  Spraying  for  Scale  Insects. 

167.  Manufacture  of  Dry  Wines  in  Hot  Countries. 

168.  Observations  on  Some  Vine  Diseases  in  Sonoma  County. 

169.  Tolerance  of  the  Sugar  Beet  for  Alkali. 

170.  Studies  in  Grasshopper  Control. 

171.  Commercial  Fertilizers.     (June  30,  1905.) 

172.  Further  Experience  in  Asparagus  Rust  Control. 

173.  Commercial  Fertilizers.     (December,  1905.) 

174.  A  New  Wine-Cooling  Machine. 

175.  Tomato  Diseases  in  California. 

176.  Sugar  Beets  in  the  San  Joaquin  Valley. 

177.  A  New  Method  of  Making  Dry  Red  Wine. 

178.  Mosquito  Control. 

179.  Commercial  Fertilizers.     (June,  1906.) 

180.  Resistant  Vineyards. 

181.  The  Selection  of  Seed- Wheat. 

182.  Analyses  of  Paris  Green  and  Lead  Arsenate.    Proposed  Insecticide  Law. 

183.  The  California  Tussock  Moth. 

184.  Report  of  the  Plant  Pathologist. 

185.  Report  of  Progress  in  Cereal  Investigations. 

Circulars. 

No.      1.  Texas  Fever. 

2.  Blackleg. 

3.  Hog  Cholera, 

4.  Anthrax. 

5.  Contagious  Abortion  in  Cows. 
7.  Remedies  for  Insects. 

9.  Asparagus  Rust. 

10.  Reading  Course  in  Economic  Entomology.     (Revision.) 

11.  Fumigation  Practice. 

12.  Silk  Culture. 

13.  The  Culture  of  the  Sugar  Beet. 

15.  Recent  Problems  in  Agriculture.     What  a  University  Farm  is  For. 

16.  Notes  on  Seed- Wheat. 

17.  Why  Agriculture  Should  be  Taught  in  the  Public  Schools. 

18.  Caterpillars  on  Oaks. 

19.  Disinfection  of  Stables. 

20.  Reading  Course  in  Irrigation. 

21.  The  Advancement  of  Agricultural  Education. 

22.  Defecation  of  Must  for  White  Wine. 

23.  Pure  Yeast  in  Wineries. 

24.  Olive  Pickling. 

25.  Suggestions  Regarding  Examination  of  Lands. 

26.  Selection  and  Preparation  of  Vine  Cuttings. 

27.  Marly  Subsoils  and  the  Chlorosis  or  Yellowing  of  Citrus  Trees. 

Copies  may  be  had  on  Application  to  DIRECTOR  OF  EXPERIMENT  STATION, 

Berkeley,  Calif. 


UNIVERSITY   OF  CALIFORNIA   PUBLICATIONS. 

COLLEGE  OF  AGRICULTURE, 

AGRICULTURAL  EXPERIMENT  STATION, 

BERKELEY,  CALIFORNIA. 


INSECTS  INJURIOUS  TO  THE  VINE 
IN  CALIFORNIA. 


Phylloxera  (Phylloxera  vastatrix  Plan.).  Flea  Beetles  (Haltica  sps.). 

Grape  Leaf  Hopper  (Typhlocyba  comes  Say).  Grape  Leaf- folder  (Desmia  funeralis  Hubn.). 

Imported  Grape  Root  Worm  (Adoxus  vitis  Leaf  Chafers. 

Foureroy).  Wire  Worms. 

Hawk  Moth  Larvae.  Erinose. 

Grasshoppers.  Nematode  Root  Gall)  Heterodera  radicola 

Cut  Worms  and  Army  Worms.  (Greef)  Mull.). 


BY  H.  J.  QUAYLE. 


BULLETIN    No.    192, 

(Berkeley,  Cal.,  October,  1907.) 


SACRAMENTO: 

w.  w.  SHANNON,     :     :     :     :     SUPERINTENDENT  STATE  PRINTING. 

1907. 


BENJAMIN  IDE  WHEELER,  Ph.D.,  LL.D.,  President  of  the  University. 


EXPERIMENT     STATION     STAFF. 

E.   J.   WICKSON,  M.A.,   Director  and  Horticulturist. 

E.  W.  HILGARD,   Ph.D.,  LL.D.,   Chemist. 

W.   A.   SETCHELL,   Ph.D.,   Botanist. 

ELWOOD  MEAD,  M.S.,  C.E.,  Irrigation  Engineer. 

C.  W.  WOODWORTH,  M.S.,  Entomologist. 

R.    H.    LOUGHRIDGE,    Ph.D.,    Agricultural    Geologist    and    Soil    Physicist.       (Soils, 

Alkali.) 

M.  E.  JAFFA,  M.S.,  Nutrition  Expert,  in  charge  of  the  Poultry  Station. 
G.  W.  SHAW,  M.A.,  Ph.D.,  Agricultural  Technologist,  in  charge  of  Cereal  Stations. 
GEORGE  E.  COLBY,  M.S.,  Chemist.      (Fruits,  Waters,  Insecticides.) 
RALPH  E.  SMITH,  B.S.,  Plant  Pathologist  and  Superintendent  of  Southern  California 

Pathological  Laboratory  and  Experiment   Station. 
A.   R.   WARD,   B.S.A.,   D.V.M.,   Veterinarian  and  Bacteriologist. 

E.  W.  MAJOR,   B.Agr.,  Animal  Industry  and  Manager  of   University  Farm. 

F.  T.   BIOLETTI,   M.S.,   Viticulturist.      (Grapes,   Wine  and  Zymology.) 
H.  M.  HALL,   M.S.,  Assistant  Botanist. 

H.   J.   QUAYLE,  A.B.,   Assistant  Entomologist. 

W.    T.    CLARKE,    B.S.,    Assistant    Horticulturist    and    Superintendent    of    University 

Extension  in  Agriculture. 

JOHN  S.  BURD,  B.S.,  Chemist,  in  charge  of  Fertilizer  Control. 
C.  M.  HARING,  D.V.M.,  Assistant  Veterinarian  and  Bacteriologist. 

J.    W.    MILLS,    Assistant   Horticulturist,     )      Citrus  Experiment  station,  Riverside. 

T.  F.  HUNT,  B.S.,      "  ) 

E.   B.   BABCOCK,   B.S.,  Assistant  Plant  Pathologist. 

E.  H.  SMITH,  M.S.,  Assistant  Plant  Pathologist. 

H.  J.  RAMSEY,  M.S.,  Assistant  Plant  Pathologist,  )     Southern  California  Pathologi- 

C.   O.    SMITH,   M.S.,  "  "  f        cal  Laboratory.     Whittier. 

R.  E.  MANSELL,  Assistant  in  Horticulture,  in  charge  of  Central  Station   Grounds. 

GEO.  W.   LYONS,  B.S.,   Assistant  in  Soil  Laboratory. 

RALPH  BENTON,  B.S.,  Assistant  in  Entomology. 

A.  J.  GAUMNITZ,  M.S.,  Assistant  in  Cereal  Investigations. 

HANS  C.  HOLM,  B.S.,  Assistant  in  Zymology. 

P.  L.  McCREARY,  B.S.,  Laboratory  Assistant  in  Fertiliser  Control. 

C.  WESTERGAARD,    B.S.,  Assistant  in  Farm  Mechanics. 

M.  E.  STOVER,  B.S.,  Assistant  in  Agricultural  Chemical  Laboratory. 
RACHAEL  CORR,  M.A.,  Assistant  in  Cereal  Laboratory. 

D.  R.  HOAGLAND,  A.B.,  Assistant  in  Agricultural  Chemical  Laboratory. 
D.  L.  BUNNELL,  Clerk  to  the  Director. 


JOHN  TUOHY,  Patron,  )          Tulare  Substatiori(  Tulare. 

J.  T.  BEARSS,  Foreman,  \ 

J.  W.  ROPER,  Patron,  )          University  Forestry  Station,  Chico. 

E.  C.  MILLER,  In  charge,        } 

\          U"1™™*  Forest^  Station'  Santa 

VINCENT    J.     HUNTLEY,    Foreman     of    California     Poultry     Experiment     Station, 
Petaluma. 

The  Station  publications  (REPORTS  AND  BULLETINS),  so  long  as  avail- 
able, will  be  sent  to  any  citizen  of  the  State  on  application. 


INSECTS  INJURIOUS  TO  THE  VINE  IN  CALIFORNIA. 

BY  H.  J.  QUAYLE. 


California,  with  its  extensive  areas  of  vineyards  and  lack  of  extremes 
in  climate,  offers  suitable  conditions  for  the  development  of  a  con- 
siderable number  of  insect  pests  of  the  vine.  Here  also  the  large 
plantings  of  the  European,  or  vinifera,  vines  have  given  the  phylloxera 
an  opportunity  to  do  greater  damage  than  elsewhere  in  the  United 
States. 

Of  the  two  hundred  and  seventy-five  insects  we  have  recently  listed 
as  attacking  the  vine  throughout  the  world,  only  a  very  few  (a  dozen 
or  two)  are  really  of  any  economic  importance;  all  the  others  being, 
generally,  but  casual  visitants.  Two  or  three  of  these  of  economic 
importance  attack  the  roots,  while  the  remainder  feed  upon  the  parts 
of  the  plant  above  ground. 

The  roots  are  sapped  of  their  juices,  rendered  knotty,  and  caused  to 
decay  by  the  phylloxera.  Strips  or  rings  of  the  bark  are  eaten  out  by 
the  root  worm,  and  the  fibrous  roots  are  devoured  by  wire  worms. 
The  juices  of  the  leaves  are  sucked  out  by  the  vine  hoppers,  irregular 
holes  eaten  away  by  flea  beetles  and  leaf  chafers,  or  chain-like  strips 
by  the  root  beetles ;  the  edges  rolled  by  the  leaf -roller,  or  the  foliage 
devoured  completely  by  hawk  moth  larvas,  grasshoppers,  cut  worms  and 
army  worms.  The  young  buds  are  destroyed  by  the  flea  beetle  and  by 
cut  worms ;  and  the  shoots,  petioles,  pedicels,  and  berries  have  chain-like 
furrows  gouged  out  by  the  root  beetle. 

With  the  possible  exception  of  the  root  beetle,  all  the  insects  attacking 
the  vines  in  this  State  are  native  American  insects.  The  present 
bulletin  is  intended  to  give  simply  a  popular  account  of  the  more 
important  of  these.  More  or  less  extended  studies  have  been  carried  on 
during  the  past  year  on  the  vine  hopper  and  root  beetle,  and  these 
will  be  treated  of  in  separate  bulletins  and  only  summary  accounts 
given  here. 

PHYLLOXERA.* 

(Phylloxera  vastatrix  Planchon.) 

Historical. — The  phylloxera  is  a  native  of  the  United  States  east  of 
the  Rocky  Mountains,  where  it  is  found  living  upon  the  wild  vines.  It 
ir?  a  minute  insect,  related  to  the  scale  insects  and  plant  lice. 

The  insect  was  probably  introduced  into  California  upon  vines,  cut- 
tings or  roots,  imported  from  France,  though  it  was  possibly  introduced 

*  Revised  from  Bulletin  No.  131,  by  F.  T.  Bioletti. 


100 


UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 


from  several  sources  and  at  several  points.  It  was  first  noticed  in  the 
southern  part  of  Sonoma  County,  in  the  valley  surrounding  the  old 
town  of  Sonoma,  about  1874.  By  1880  vines  killed  by  the  insect  had 
been  found  in  Napa,  Solano,  and  Placer  counties,  and  hundreds  of 
acres  had  been  pulled  up  in  Sonoma  Valley.  Since  then  the  insect  has 
spread  to  all  the  important  grape-growing  regions  of  California  north 
of  Tehachapi*,  and  probably  not  less  than  fifty  thousand  acres  have 
been  destroyed. 

The  Insect. — The  phylloxera  occurs  normally  in  four  forms,  which 
have  been  called  by  Victor  Mayet: 

1.  The  gall  insect,  or  form  of  multiplication; 

2.  The  root  insect,  or  form  of  devastation; 

3.  The  winged  insect,  or  form  of  colonization ; 

4.  The  sexual  insect,  or  form  of  regeneration. 

The  gall  insect  lives  upon  the  leaves,  and  is  the  commonest  form  on 
the  wild  vines  in  the  native  habitat  of  the  insect.  It  rarely  or  never 

occurs  in  California.  In  Europe 
it  is  found  often  upon  American 
and  rarely  upon  European  varie- 
ties. It  causes  little  swellings  or 
galls  upon  the  leaves  and 
younger  parts  of  the  vine,  which, 
though  sometimes  very  numer- 
ous, do  little  permanent  injury. 
The  chief  danger  from  the  gall 
form  is  that  it  multiplies  with 
astonishing  rapidity  and  mi- 
grates from  the  leaves  to  the  soil. 
Here  it  attacks  the  roots  and 
gives  rise  to  the  root  form,  which 
is  the  "form  of  devastation," 
the  one  which  finally  destroys 
all  the  vines  it  attacks  which  are 
' '  non-resistant. ' '  Every  insect  of  the  root  form  which  reaches  maturity 
lays  about  twenty-five  or  thirty  eggs,  each  of  which  is  capable  of 
developing  into  a  new  egg-layer  needing  no  fertilization.  As  there  are 
from  five  to  seven  such  generations  during  the  year  the  increase  in 
numbers  is  extremely  rapid. 

Sometimes  during  the  summer,  usually  in  July  or  August,  some  of 
the  eggs  laid  by  the  root  insects  may  develop  into  insects  of  slightly 
different  form,  called  nymphs.  They  are  somewhat  larger  than  the 

*  The  phylloxera  is  said  to  have  been  found  once  in  Southern  'California,  but  as 
the  vineyard  was  uprooted  and  destroyed  the  insect  was  probably  extirpated. 


FIG.  1.  Under  side  of  grape  leaf  showing  galls 
caused  by  Phylloxera.  This  form  seldom,  if 
ever,  occurs  in  California. 


BULLETIN  192. 


INSECTS    INJURIOUS    TO    THE   VINE. 


101 


normal  root  form  and  show  slight  protuberances  on  the  sides,  which 
finally  develop  into  wings.  These  are  the  winged  or  colonizing  insects, 
which  emerge  from  the  soil,  and,  though  possessing  very  weak  powers 
of  flight,  are  capable  of  sailing  a  short  distance,  and  if  a  wind  is 
blowing  may  be  taken  many  rods,  or  even  miles.  Those  which  reach 
a  vine  crawl  to  the  under  side  of  a  leaf  and  deposit  from  three  to  six 
eggs.  These  eggs  are  of  two  sizes,  the  smaller  of  Avhich  produce  males 
and  the  larger  females.  The  females  arising  from  these  eggs,  after 
fertilization,  migrate  to 
the  rough  bark  of  the 
two-year-old  wood,  where 
each  deposits  a  single 
egg,  called  the  winter 
egg,  which  remains  upon 
the  vine  until  the  fol- 
lowing spring.  The  in- 
sect which  hatches  from 
this  egg  in  the  spring 
goes  either  to  the  young 
leaves  and  becomes  a 
gall-maker,  or  descends 
to  the  roots  and  gives 
rise  to  a  new  generation 
of  egg-laying  root-feed- 
ers. 

The  normal  and  com- 
plete life  cycle  of  the 
phylloxera  appears  then 
to  be  as  follows:  Male 
and  female  insects  (one 

generation   in    autumn)  ;     FIG-  2    .Root'Form  of  Phylloxera,    a,  healthy  root;  6,  root 


on  which  the  lice  are  working,  representing  the  knots  and 
swellings  caused  by  their  punctures ;  c,  root  deserted  by 
lice  and  beginning  to  decay ;  d,  d,  d,  show  how  the  lice 
appear  on  the  larger  roots ;  e,  the  nymph ;  g,  winged  female. 
After  Riley. 


gall  insects  (one  to  five 
generations  while  the 
vines  are  in  leaf)  ;  root 
insects  (an  unknown  number  of  generations  throughout  the  year)  ; 
nymphs,  which  become  winged  insects  (one  generation  in  midsummer). 
The  gall  stage  may  be  omitted,  as  it  generally  is  in  California,  and  the 
insects  which  hatch  from  the  fertilized  eggs  laid  by  the  female  go 
directly  to  the  root  and  produce  offspring,  which  are  indistinguishable 
from  the  root  form  produced  in  the  normal  cycle.  For  how  many 
generations  the  root  form  can  exist  and  reproduce  without  invigoratioh 
supposed  to  come  from  the  production  of  the  sexual  form  is  not  known, 
but  certainly  for  four  years  and  probably  more.  The  gall  form  on 


102  UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 

American  vines  may  probably  be  prevented  by  spraying  the  vines  in 
winter  to  kill  the  winter  eggs ;  but  this  treatment  has  no  effect  on  the 
root  forms,  which  in  California  hibernate  abundantly  in  the  soil. 

All  forms  of  the  phylloxera  are  extremely  minute,  the  root  form 
being  about  one  twenty-fifth  of  an  inch  long  when  it  reaches  the  adult 
egg-laying  stage,  and  little  more  than  half  this  length  when  young  and 
active.  It  is  just  large  enough  to  be  seen  by  the  unaided  eye  in  a 
good  light  when  its  presence  is  known,  and,  by  the  help  of  a  glass 
magnifying  five  diameters,  its  legs  and  antennae  are  plainly  visible. 
Its  color  is  light  greenish-yellow  in  summer,  and  somewhat  darker  in 
winter;  so  that  when  numerous  the  attacked  roots  appear  as  though 
dusted  in  spots  with  powdered  mustard  or  cinnamon.  The  newly 
hatched  insect  is  fairly  active,  and  at  first  moves  about  from  place 
to  place  on  the  roots,  but  finally,  when  it  reaches  the  egg-laying  stage, 
inserts  its  sucking-tube  into  the  root  and  remains  fixed. 

Nature  of  Injury. — The  amount  of  nutriment  taken  from  the  vine 
by  such  minute  insects,  even  when  present  in  the  immense  numbers  in 
which  they  sometimes  occur,  is  not  sufficient  to  account  for  the  dis- 
astrous effect  upon*  the  plant.  The  death  of  the  vine  is  due  to  the 
decay  which  sets  in  wherever  the  phylloxera  inserts  its  sucking-tube, 
for  a  swelling  is  produced,  composed  of  soft  tissue,  which  soon  decays. 
When  this  swelling  occurs  at  the  end  of  a  young  rootlet,  growth  in 
length  is  stopped ;  when  it  occurs  on  larger  roots,  a  kind  of  ' '  cancer ' ' 
or  decay  spot  is  finally  formed,  which  soon  extends  around  the  root, 
and  all  below  the  point  of  attack  diest 

During  the  first  year  or  two  after  a  vine  is  attacked  there  is  little 
apparent  damage.  In  fact,  the  effect  of  the  phylloxera  is  equivalent 
to  root  pruning,  and  in  some  cases  results  in  an  unusually  large  crop 
of  grapes.  The  year  after  this  crop,  however,  the  vine  having  endured 
the  double  strain  of  heavy  bearing  and  root  injury,  is  unable  to 
recuperate,  and  generally  dies.  In  rich  moist  soil  the  death  of  the 
vine  is  not  so  sudden,  and  two  or  even  more  crops  may  mature  after 
symptoms  of  the  disease  are  evident. 

Methods  of  Dispersal.  —  The  ways  in  which  new  vines  and  vineyards 
become  infested  may  be  classed  as  natural  and  artificial.  The  natural 
ways  may  be  inferred  from  what  has  been  said  of  the  life  history  of 
the  insect.  From  a  vine  first  attacked  the  root  form  spreads  through 
the  soil  to  neighboring  vines  slowly,  but  continuously,  thus  forming 
the  so-called  ' '  oil-spots. ' '  A  typical  oil-spot  of  several  years '  standing 
will  show  several  dead  vines  in  the  center,  then  a  ring  of  vines  with 
very  short  growth  and  no  grapes,  next  another  ring  where  the  growth 
is  not  of  normal  vigor,  but  where  the  crop  may  be  equal  to  or  larger 


BULLETIN  192.  INSECTS  INJURIOUS  TO  THE  VINE.  103 

than  that  of  the  healthy  vines.  Such  a  spot  enlarges  its  area  year  after 
year  at  a  gradually  accelerating  rate  as  the  front  of  the  invading  army 
becomes  longer.  The  rate  of  advance  will  vary  with  the  soil  and  climate, 
but  will  probably  never  exceed  forty  or  fifty  feet  annually.  If  this 
were  its  only  method  of  spreading,  the  insect  could  be  controlled  or  even 
exterminated  with  comparative  ease.  Unfortunately,  it  is  able  to 
spread  much  more  rapidly  by  means  of  the  winged  form;  and  the 
rapidity  of  its  extension  over  the  south  of  France  was  due  principally 
to  this  agency.  In  California,  though  the  winged  form  has  been  found, 
it  seems  to  be  rare,  especially  in  the  central  valleys,  which  probably 
accounts  for  the  comparative  slowness  with  which  new  districts  have 
become  infested.  The  artificial  methods  of  dispersal  here  are  probably 
more  effectual  in  spreading  the  insect  than  the  natural.  The  insects 
are  taken  from  one  part  of  the  vineyard  to  another  on  pieces  of  the 
roots  of  infested  vines  adhering  to  the  plows  or  other  implements  used 
in  cultivation;  while  they  are  introduced  into  new  localities  on  rooted 
vines  or  cuttings  brought  from  infested  districts. 

METHODS    OF    COMBATING    THE    PHYLLOXERA. 

The  methods  to  be  used  in  resisting  this  foe  of  the  vineyardist  may 
be  divided  into  groups  corresponding  to  different  stages  of  infestation 
and  to  varying  local  conditions.  There  are  three  cases  to  be  distin- 
guished, viz :  1.  When  the  district  is  uninf ested ;  2.  When  a  few  small 
infested  spots  are  known  in  the  district;  3.  When  the  district  is  badly 
infested;  i.  e.,  shows  many  and  widely  distributed  infested  spots,  even 
though  none  of  the  spots  are  large. 

1.  In  the  first  case,  all  efforts  should  be  directed  to  keeping  out  the 
pest,  and  the  only  effectual  means  is  a  rigidly  enforced  embargo  on  all 
material  capable  of  introducing  it.    Although  the  phylloxera,  so  far  as 
known,  feeds  on  nothing  but  the  vine,  there  is  always  danger  of  eggs 
or  insects  being  contained  in  the  earth  attached  to  any  kind  of  root. 
This  measure,  consistently  carried  out,  has  kept  the  province  of  Algiers 
free  from  infestation,  though  the  neighboring  province  of  Constantine 
has  been  a  prey  to  the  pest  for  many  years. 

2.  In  the  second  case,  where  the  insect  has  already  obtained  a  foot- 
hold, the  first  step  to  take  is  to  determine  as  nearly  as  possible  the 
exact  extent  of  the  infested  area.     If  it  is  found  to  be  confined  to  a 
small,  isolated  vineyard,  an  effort  should  be  made  to  completely  eradi- 
cate the  pest.     This  can  be  done  only  by  destroying  the  vineyard,  by 
subjecting  it  to  what  is  called  the  "death  treatment."     This  is  best 
done  (after  grubbing  up  the  vines  and  burning  them  on  the  ground) 
by   making   an   embankment   around   the   whole    vineyard   and   then 
running  water  on  to  it  until  it  is  converted  into  a  lake.     The  water 


104  UNIVERSITY  OF   CALIFORNIA — EXPERIMENT   STATION. 

should  be  kept  continuously  at  a  depth  of  at  least  six  inches  until  all 
the  insects  are  destroyed.  The  best  time  to  do  this  is  in  May  or  June, 
as  at  that  time  four  weeks  of  continuous  flooding  is  sufficient  to  kill 
both  insects  and  roots.  It  is  important  that  every  root  should  be  killed 
in  order  that,  if  any  insect  survives  the  flooding,  it  will  die  for  lack  of 
food.  Where  flooding  is  impracticable,  the  vines  should  be  grubbed 
out  and  burned  in  the  same  way,  and  the  ground  kept  clean  of  all 
growth  for  at  least  one  year.  This  is  in  order  that  any  suckers  which 
may  come  up  from  the  roots  may  be  destroyed  immediately.  If  crops, 
or  even  weeds,  are  allowed  to  grow,  some  of  these  suckers  may  escape 
observation  and  keep  the  insects  alive  to  spread  the  pest  the  next 
year.  If  the  affected  spot  is  not  too  large  it  is  well  to  disinfect  the  soil 
with  bisulfid  of  carbon.  This  is  applied  by  pouring  one  ounce  each 
into  holes  placed  two  feet  apart  all  over  the  land  to  be  treated.  These 
holes  should  be  about  one  foot  deep  and  can  be  made  with  a  small 
crowbar  or  dibble.  After  pouring  in  the  liquid,  the  hole  should  be 
closed  by  pressing  the  earth  into  it  with  the  foot. 

If,  however,  the  pest  has  obtained  a  foothold  in  several  vineyards  of 
the  district,  or  in  a  large  vineyard,  it  is  practically  hopeless  to  attempt 
to  eradicate  it.  In  this  case  all  we  can  reasonably  hope  to  do  is  to  delay 
the  spread  of  the  pest  as  much  as  possible,  and  in  the  meantime  to  place 
all  new  vineyards  on  a  permanently  phylloxera-resistant  basis.  Every 
infested  spot  in  the  district  should  be  diligently  sought  out  and  treated. 
The  treatment  consists  in  digging  up  and  burning  every  vine  in  each 
spot  which  shows  symptoms  of  attack,  together  with  at  least  three  rows 
of  apparently  healthy  vines  surrounding  them.  Disinfection  of  the 
soil  of  these  spots  by  flooding  or  with  bisulfid  of  carbon  is  then  advisable 
wherever  practicable,  but  in  any  case  these  spots  should  be  strictly 
isolated  in  all  farming  operations.  In  cultivating  the  healthy  parts 
of  the  vineyard,  to  pass  through  the  infested  spots  with  plows  or  hoes 
is  a  most  effective  method  of  accelerating  the  spread  of  the  insect. 

The  search  for  infested  spots  is  most  easily  and  thoroughly  done  in 
July,  or  August,  as  at  that  time  the  shortness  of  growth  in  the  "  oil- 
spots  ' '  is  most  readily  detected  and  the  insects  are  easily  found,  as  they 
are  in  large  numbers  on  the  surface  roots  and  generally  also  on  the 
trunk  of  the  vine  just  below  the  surface  of  the  soil.  The  search  for  and 
destruction  of  infested  spots  should  be  .repeated  every  year;  and  if 
commenced  in  the  early  stages  of  infestation  and  prosecuted  with 
sufficient  thoroughness  in  every  vineyard  throughout  a  district,  will 
effectually  prolong  the  life  of  the  bulk  of  the  vines  for  many  years. 
As  soon  as  the  actual  presence  of  the  phylloxera  in  a  district  is  known 
and  all  hope  of  permanently  eradicating  it  is  abandoned,  the  embargo 
should  be  modified  to  the  extent  of  admitting  vine  cuttings.  These 


BULLETIN  192.  INSECTS  INJURIOUS  TO  THE  VINE.  105 

should  be  introduced,  however,  under  strict  quarantine  regulations, 
including  disinfection  by  responsible  and  properly  instructed  persons. 
Rooted  vines,  or  cuttings  with  pieces  of  old  wood  attached,  should  still 
be  kept  out,  as  they  can  not  be  disinfected  with  any  certainty. 

3.  However  conscientiously  and  completely  these  measures  are  en- 
forced, a  time  will  arrive  sooner  or  later  when  the  cost  of  inspection  and 
eradication  will  be  greater  than  any  benefit  to  be  derived  from  them. 
We  are  then  face  to  face  with  the  third  set  of  conditions;  we  must 
accept  the  phylloxera  as  a  permanent  inhabitant  of  the  district,  and 
simply  consider  the  best  method  of  growing  our  vines  in  spite  of  its 
presence.  By  this  time  all  embargo  or  quarantine  regulations  are 
useless  and  should  be  repealed. 

Of  the  many  thousands  of  methods  proposed  and  tested  for  maintain- 
ing a  vineyard  in  spite  of  the  phylloxera,  but  very  few  have  been  of  the 
slightest  practical  value,  and  only  four  are  at  present  used  to  any 
important  extent.  These  methods  are: 

1.  Injection  of  carbon  bisulfid; 

2.  Flooding 'or  submersion; 

3.  Planting  in  sand; 

4.  Planting  resistant  vines. 

The  first  two  methods  aim  at  destroying  the  insect;  the  last  two  at 
rendering  the  vines  immune  to  their  attack.  As  neither  of  the  insecti- 
cidal  methods  can  be  applied  with  sufficient  thoroughness  to  completely 
eradicate  the  pest  without  also  killing  the  vines,  the  treatments  have  to 
be  repeated  every  year  in  order  to  destroy  the  offspring  of  the  few 
insects  which  escaped  the  treatment  of  the  previous  year.  For  this 
reason  these  methods  are  being  abandoned  everywhere,  especially  in  all 
new  plantings,  in  favor  of  the  others,  which  after  the  vineyard  is  prop- 
erly started,  involve  no  further  expense;  and  as  planting  in  sand  is  of 
very  limited  and  local  applicability,  it  may  be  said  that  at  present  the 
only  method  that  need  concern  grape-growers  in  California  very  seri- 
ously is  the  use  of  resistant  vines. 

Bisulfid  of  Carbon  Method. 

Bisulfid  of  carbon  is  a  liquid  which  volatilizes  very  rapidly  at  ordi- 
nary temperatures  and  gives  off  a  poisonous  and  highly  inflammable 
vapor.  This  vapor  is  heavier  than  air  and  therefore  gradually  replaces 
and  saturates  the  air  in  the  interstices  of  the  soil  when  the  liquid  is 
injected.  It  is  used  at  the  rate  of  from  one  hundred  and  twenty-five 
pounds  to  two  hundred  and  fifty  pounds  per  acre,  and  may  be  applied 
at  any  time  except  during  blossoming  and  ripening  of  the  fruit.  Two 
treatments,  one  directly  after  the  vintage  and  the  other  a  week  or  so 
before  blossoming,  give  the  best  results.  The  liquid  is  applied  by  pour- 
ing from  one-fourth  to  three-fourths  of  an  ounce  into  holes  made  from 


106  UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 

18  to  24  inches  apart  all  over  the  vineyard,  care  being  taken  not  to 
put  any  nearer  than  one  foot  from  a  vine.  The  holes  are  made  from 
12  to  15  inches  deep,  and  are  closed  immediately  after  pouring  in  the 
liquid  by  pressing  the  soil  with  the  foot.  The  holes  may  be  made  with 
an  iron  rod  or  dibble;  but,  where  the  method  is  employed  on  a  large 
scale,  special  injectors  are  used,  which  much  facilitate  the  work.  The 
injections  are  best  made  when  the  soil  is  fairly  firm,  and  when  it  is 
neither  very  wet  nor  very  dry.  This  method  succeeds  only  in  rich, 
deep,  loose  soils,  and  can  not  be  used  successfully  in  soil  containing 
much  clay,  or  on  dry,  rocky  hillsides  or  when  the  soil  is  saturated 
with  moisture.  It  is  most  effective  in  sandy  soils,  where  the  nature 
of  the  soil  is  itself  unfavorable  to  the  insect.  It  is  least  success- 
ful in  warmer  locations,  where  the  insect  is  most  prolific  and  most 
harmful,  and  is  used  chiefly  in  the  cooler  locations  where  the 
phylloxera  does  least  damage.  Vines  which  are  much  weakened  by  the 
attacks  of  the  insects  can  not  be  successfully  treated,  and  all  treated 
vines  require  fertilization  and  most  thorough  cultivation.  The  annual 
cost  for  material  alone  would  be  from  $15  to  $25  per  acre;  at  the  present 
market  price  of  carbon  bisulfid. 

Submersion  Method. 

Submersion  is  a  cheaper  and  more  effective  method  of  controlling 
the  phylloxera,  but  is  necessarily  applicable  to  but  few  locations,  and 
even  where  most  successful  is  gradually  giving  way  to  the  more  satis- 
factory use  of  resistant  vines.  Its  chief  use  is  to  preserve  vineyards 
which  are  already  in  bearing,  and  it  may  be  of  use  temporarily  in  some 
locations  in  California.  In  submersion  the  vineyard  must  be  continu- 
ously covered  with  at  least  six  inches  of  water,  as  the  object  is  to  drown 
the  insects,  that  is,  to  kill  them  by  depriving  them  of  air.  If  the  sur- 
face becomes  exposed  even  for  a  brief  period,  air  will  be  absorbed  and 
the  insects  given  a  new  lease  of  life.  In  very  porous  soils  submersion 
is  impracticable  on  account  of  the  large  amount  of  water  required,  and 
ineffective  for  the  reason  that  the  rapid  passage  of  the  water  carries 
sufficient  air  into  the  soil  to  keep  the  insects  alive.  Submersion  is 
most  effective  in  destroying  the  insects  when  they  are  in  their  most 
active  condition,  that  is,  in  summer.  At  this  time,  unfortunately,  the 
vine  is  also  most  sensitive  to  injury.  The  most  favorable  time,  then, 
for  submersion  is  as  soon  as  the  vines  have  ceased  active  growth  and 
before  the  phylloxera  have  entered  their  hibernating  or  dormant  con- 
dition. This  in  most  parts  of  California  will  be  some  time  in  Novem- 
ber. At  this  period  the  flooding  need  last  but  a  week  or  ten  days;  a 
month  later,  two  or  three  weeks;  while  during  the  remainder  of  the 
winter  little  good  results  unless  the  submersion  is  prolonged  for  thirty- 


BULLETIN  192.  INSECTS  INJURIOUS  TO  THE  VINE.  107 

five  or  forty  days,  and  indeed  in  some  soils  of  the  extreme  south  of 
France  two  months  has  been  found  necessary.  As  the  insect  is  most 
susceptible  in  midsummer,  it  was  at  one  time  thought  that  a  copious 
irrigation  at  that  time  sufficient  to  destroy  most  of  the  insects  without 
injuring  the  vines  could  be  effected.  At  present  a  flooding  in  July  for 
not  exceeding  forty-eight  hours  is  practiced  in  a  few  places,  but  only  to 
supplement  winter  flooding,  or  the  injection  of  bisulfid.  The  insecti- 
cidal  value  of  the  short  submersion  which  the  vines  will  withstand  at 
this  time  seems  to  be  very  slight.  Its  main  value  seems  to  be  in 
prompting  a  vigorous  growth  of  new  rootlets  to  replace  those  that  have 
been  injured. 

Planting  in  Sand  Method. 

Though  no  thoroughly  satisfactory  explanation  has  been  given,  the  fact 
is  established  that  in  certain  very  sandy  soils  vines  are  uninjured  by 
phylloxera.  All  sandy  soils  are  unfavorable  to  the  increase  of  the 
insect,  and  vines  planted  in  them  die  more  slowly  than  in  others;  but 
for  complete  immunity  the  soil  must  contain  at  least  sixty  per  cent  of 
siliceous  sand.  The  looser  and  more  fine-grained  the  sand,  the  more 
resistance  it  offers  to  the  insect.  Sands  containing  notable  quantities 
of  clay,  all  those  in  fact  which  have  a  tendency  to  form  lumps  or 
"  cake,"  offer  less  resistance. 

Resistant   Vines. 

The  most  satisfactory  method  of  combating  phylloxera  is  the  use  of 
resistant  vines,  because  it  is  applicable  to  all  conditions  and  is  the  most 
economical  in  the  end.  A  resistant  vine  is  one  which  is  capable  of 
keeping  alive  and  growing  even  when  phylloxera  are  living  upon  its 
roots.  Its  resistance  depends  on  two  facts:  1st,  that  the  insects  do  not 
increase  so  rapidly  on  its  roots;  and,  2d,  that  the  swellings  of  diseased 
tissue  caused  by  the  punctures  of  the  insects  do  not  extend  deeper  than 
the  bark  of  the  rootlets  and  are  sloughed  off  every  year,  leaving  the 
roots  as  healthy  as  before.  The  wild  vines  of  the  Mississippi  valley 
states  have  evolved  in  company  with  the  phylloxera,  and  it  is  naturally 
among  these  that  we  find  the  most  resistant  forms.  No  vine  is  per- 
fectly immune  in  the  sense  that  phylloxera  will  not  attack  it  at  all; 
but  on  the  most  resistant  the  damage  is  so  slight  as  to  be  impercep- 
tible. The  European  vine  ( Vitis  vinifera  L.)  is  the  most  susceptible  of 
all,  and  all  the  grapes  cultivated  in  California,  with  a  few  unimportant 
exceptions,  belong  to  this  species.  Between  these  two  extremes  we  find 
all  degrees  of  resistance,  which  is  expressed  by  a  series  of  numbers 
ranging  from  20,  indicating  the  highest  possible  resistance,  to  0,  indi- 
cating the  utmost  susceptibility.  The  following  table  shows  the  resist- 


108 


UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 


ance  (according  to  Viala  and  Ravaz  and  other  authorities)  of  some  of 
the  best  known  species  and  varieties: 

Comparative  Resistance  to  Phylloxera. 


SPECIES — WILD  VINES. 


CULTIVATED    VARIETIES    AND    HYBRIDS. 


Vitis  rotundif olia   19 

Vitis  vulpina    (Riparia) 18 

Vitis  rupestris   18 

Vitis  Berlandieri   17 

Vitis  sestivalis 16 

Vitis  labrusca   5 

Vitis  californica   4 

Vitis  vinifera   .  0 


Gloire  de  Montpellier  (Riparia)  ....  18 

Riparia   X   Rupestris  3309 18 

Rupestris    Martin 18 

Rupestris  St.  George 16 

Riparia   X    Solonis   1616 16 

Solonis     14 

Lenoir    12 

Isabella    5 


The  degree  of  resistance  necessary  for  the  production  of  good  crops 
varies  with  the  character  of  the  soil.  The  resistance  expressed  by  the 
numbers  16  to  20  is  sufficient  for  all  soils.  A  resistance  of  14  or  15  is 
sufficient  in  sandy  and  moist,  rich  soils,  where  the  vine  can  readily 
replace  the  rootlets  as  fast  as  they  are  destroyed.  Fairly  successful 
vineyards  have  been  established  with  vines  having  a  resistance  of 
less  than  14,  but  as  the  vines  become  old  the  lack  of  resistance  is 
generally  shown  by  a  weakening  of  the  vine  and  a  falling  off  of  the 
crop.  Many  vineyards  in  the  south,  of  France  grafted  on  Lenoir  which 
formerly  bore  well,  have  now  to  be  treated  with  injections  of  bisulfid  of 
carbon.  For  the  above  reason  it  is  advisable  to  reject  all  vines  with  a 
resistance  of  13  or  under,  especially  as  vines  with  greater  resistance 
can  now  be  obtained  for  practically  all  conditions. 

Resistant  vines  are  of  two  kinds:  (a)  Those  which  are  grown  for  the 
grapes  they  produce,  and  (b)  Those  which  are  useful  only  as  stocks  on 
which  to  graft  the  non-resistant  varieties.  The  former  are  called 
"Direct  producers"  and  the  latter  "Resistant  stocks." 

(a)  Direct  Producers. — When  the  phylloxera  commenced  to  destroy 
the  vineyards  of  Europe,  the  natural  attempt  was  made  to  replace  them 
with  the  varieties  of  vines  which  had  proved  successful  in  the  United 
States,  where  the  insect  was  endemic.  These  varieties,  however,  all 
proved  unsatisfactory.  Some,  like  the  Concord  and  Catawba,  were 
insufficiently  resistant,  and  although  they  could  be  grown  where  the 
severe  cold  of  winter  impeded  the  prolificness  of  the  phylloxera,  they 
quickly  succumbed  in  the  milder  grape-growing  sections  of  Europe.* 
Most  of  them  were  poor  bearers  compared  with  the  prolific  European 
vines,  and  finally  the  character  of  their  fruit  differed  so  widely  from 

*  In  California  these  and  other  Labrusca  varieties  and  hybrids  resist  very  little 
longer  than  Vinifera  vines. 


BULLETIN  192.  INSECTS  INJURIOUS  TO  THE  VINE.  109 

what  Europeans  were  accustomed  to,  that  there  was  little  sale  for  the 
fruit,  and  the  wine  could  compete  with  only  the  very  poorest  quality  of 
Vinifera  wines,  and  brought  a  very  inferior  price.  A  few  of  the  varieties 
introduced  during  that  first  period  are  still  grown  to  a  limited  extent  in 
France,  chiefly  the  Othello  and  the  Lenoir.  They  are  being  gradually 
abandoned,  however,  as  their  crops  are  unsatisfactory,  and  in  many 
localities  can  be  maintained  only  by  the  aid  of  injections  of  bisulfid. 
For  some  years  the  search  for  a  suitable  producer  was  almost  abandoned 
by  practical  men,  the  use  of  resistant  stocks  having  been  so  fully 
successful.  Lately,  however,  renewed  efforts  have  been  made  and 
several  new  direct  producers  are  being  advocated  and  planted  to  some 
extent.  The  merit  of  these  new  varieties,  however,  is  chiefly  their 
resistance  to  Peronospora  and  black  rot.  Phylloxera  resistance  is  con- 
sidered of  much  less  importance  by  their  most  ardent  advocates,  and 
indeed  the  advice  is  generally  given  to  graft  some  of  the  best  of  these 
direct  producers  upon  phylloxera-resistant  stock. 

(b)  Resistant  Stocks. — Though  high  resistance  to  phylloxera  is  essen- 
tial in  a  grafting  stock,  there  are  other  characteristics  equally  necessary. 
The  Rotundifolia  (Scuppernong),  which  has  the  highest  resistance  of 
any  vine,  is  useless  as  a  stock  on  account  of  the  impossibility  of  grafting 
it  with  any  Vinifera  variety.  This  is  due  to  a  lack  of  affinity,  which 
means  a  lack  of  similarity  in  structure  and  composition  between  the 
tissues  of  the  stock  and  those  of  the  scion.  This  lack,  in  extreme  cases, 
results  in  an  imperfect  and  temporary  union,  but  when  not  excessive, 
only  in  a  slight  decrease  of  vigor.  The  affinity  is  not  perfect  between 
Vinifera  varieties  and  any  resistant  stock,  but  in  the  case  of  Riparia 
and  Rupestris  is  generally  sufficient  to  insure  permanence  to  the  union, 
and  the  slight  decrease  of  vigor  consequent  often  results  in  an  increase 
of  fruitfulness.  It  is  for  this  reason  that  certain  varieties  when  grafted 
on  resistant  stocks,  especially  on  Riparia,  often  bear  larger  crops  than 
when  grown  on  their  own  roots.  Not  all  varieties  of  Vinifera  have  the 
same  affinity  for  the  same  stock.  For  this  reason  it  is  desirable  to  be 
cautious  about  making  new  or  untried  grafting  combinations  on  a  large 
scale.  Some  varieties,  such  as  Carignan,  Petite  Sirah,  Clairette,  and 
Cabernet  Sauvignon,  do  excellently  on  all  stocks;  while  others,  such  as 
Mondeuse  and  Gamay,  do  not  make  a  very  good  union  with  any  of  the 
thoroughly  resistant  stocks.  The  Petit  Bouschet  and  Cinsaut  make 
very  poor  unions  with  any  variety  of  Riparia,  but  do  fairly  well  on 
Rupestris  St.  George.  The  Pinot  Noir  makes  a  vigorous  growth  upon 
Rupestris  St.  George,  but  bears  much  more  prolificacy  upon  Riparia 
Gloire;  while  the  Mataro  does  not  bear  on  Rupestris  St.  George  and 
makes  poor  unions  with  Riparia  Gloire.* 

*  Reconstitution  du  Vignoble,  par.  P.  Gervais.     1900. 


110  UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 

Selection. — A  very  serious  defect  of  many  resistant  stocks  is  a  slender 
habit  of  growth.  This  is  true  of  most  of  the  vines  found  growing  wild, 
and  cuttings  from  such  vines  make  poor  grafting  stock  for  the  stout 
Viuifera  varieties,  which  will  produce  a  trunk  four  inches  in  diameter 
while  the  stock  is  growing  only  two  inches.  This  is  particularly  true 
of  the  wild  Riparias.  For  this  reason  great  care  has  been  exercised  in 
selecting  the  stronger-growing  vines,  and  at  present  we  have  selected 
Riparia  varieties  which  almost  equal  Vinifera  in  the  stoutness  of  their 
trunks.  The  best  of  these  are  the  Riparia  Gloire  de  Montpellier  and 
Riparia  Grande  Glabre — the  first  of  which  has  given  the  best  results  in 
California. 

Adaptation. — The  European  vine  is  remarkable  among  cultivated 
plants  for  the  wide  range  of  soils  in  which  it  will  succeed.  We  find 
vineyards  producing  satisfactory  crops  on  the  lightest  sands  and  on  the 
heaviest  clays,  on  the  dry  hilltops  and  in  the  low,  moist  plains.  This 
is  not  the  case  with  resistant  stocks.  Some,  such  as  the  Rupestris  vari- 
eties, are  suited  to  the  driest  soils;  others,  like  the  Riparia  varieties, 
grow  well  only  in  rich,  moist  soils.  The  question  of  adaptation,  then, 
of  resistant  stocks  to  various  soils  is  of  the  greatest  importance  if  we 
are  to  obtain  the  best  results. 

After  rejecting  all  unselected  and  unnamed  varieties,  such  as  the 
ordinary  Rupestris  and  Riparia,  which  have  caused  so  much  disap- 
pointment and  loss  on  account  of  their  poor  growth,  and  all  insuffi- 
ciently resistant  varieties,  such  as  Lenoir,  which  have  succeeded  only 
in  the  richest  soils,  our  choice  of  a  resistant  for  a  particular  soil,  climate, 
and  scion  must  depend  on  its  qualifications  as  regards  affinity  and 
adaptation. 

After  testing  thousands  of  varieties  and  hybrids  originated  in  Europe 
and  America,  a  few  have  been  selected  as  the  best  for  practical  pur- 
poses. In  France  a  fairly  good  resistant  stock  has  been  found  for 
nearly  every  soil.  In  California  little  systematic  work  has  been  done 
in  this  respect,  and  we  still  have  the  intricate  problems  of  adaptation 
to  solve  for  most  localities.  We  can,  however,  profit  to  some  extent  by 
the  experience  of  Europe,  and  some  of  the  best  varieties  have  been 
partially  tested  here  and  give  great  promise. 

Disinfection  of  Cuttings. 

The  most  effective  method  of  treating  cuttings  suspected  of  being 
infested  with  phylloxera  is  to  expose  them  to  the  fumes  of  bisulfid  of 
carbon.  The  treatment  with  liquid  insecticides  is  not  nearly  so  reliable, 
as  Professor  Hilgard  pointed  out  many  years  ago,  on  account  of  the 
difficulty  of  wetting  the  buds  of  many  varieties,  owing  to  their  protect- 
ive covering  of  woolly  hairs. 


BULLETIN  192.  INSECTS   INJURIOUS   TO   THE   VINE.  Ill 

The  method  of  using  the  bisulfid  is  as  follows:  Place  the  cuttings  in  a 
barrel,  vat,  or  box  made  tight  by  means  of  a  thick  coat' of  paint,  or  of 
paper  pasted  on  the  inside.  On  top  of  the  cuttings  place  a  saucer  or 
other  shallow  dish,  and  into  this  pour  the  bisulfid  of  carbon.  An  ordi- 
nary saucer  will  hold  enough  for  a  box  three  feet  cube  or  a  two-hun- 
dred-gallon vat.  For  larger  receptacles  it  is  better  to  use  two  or  more 
saucers.  Deeper  vessels  will  not  do,  as  the  saturation  is  not  sufficiently 
rapid.  After  pouring  the  bisulfid  into  the  saucer,  cover  the  box  with 
an  oiled  canvas  sheet  or  other  tight-fitting  cover,  and  allow  to  stand 
for  from  forty-five  to  ninety  minutes.  At  the  end  of  this  time  there 
should  be  a  little  of  the  bisulfid  left.  If  it  has  all  evaporated  this  is 
proof  that  insufficient  was  used.  No  flame  lights  should  be  used,  as 
the  liquid  burns  easily  and  the  fumes  form  an  explosive  mixture  with 
the  air.  Care  should  be  taken  not  to  spill  any  of  the  liquid  on  the  cut- 
tings, as  it  may  kill  them.  It  is  advisable  to  cut  off  about  half  an  inch 
of  the  lower  end  of  the  treated  cuttings  before  planting,  as  the  vapor 
injures  the  open  pith.  Besides  disinfecting  the  cuttings  in  this  way,  all 
the  packing  material  in  which  they  come  should  be  burned  or,  if  valu- 
able, dipped  in  boiling  water.  Practically,  it  is  impossible  to  disinfect 
rooted  cuttings  satisfactorily  on  account  of  the  difficulty  of  killing  all 
the  phylloxera  without  seriously  injuring  the  vine  roots. 


THE  VINE  HOPPER. 

(Typhlocyba  comes  Say.) 

The  vine  hopper  (often  called  incorrectly  the  vine  thrips)  is  the  most 
widely  distributed  and  most  uniformly  present  of  all  the  grape  insects 
occurring  in  the  State.  It  occurs  in  injurious  numbers,  however,  chiefly 
in  the  Sacramento  and  San  Joaquin  valleys.  It  is  also  present  in  the 
coast  counties,  but  rarely  in  sufficient  numbers  to  do  much  injury. 
Another  larger  species  (Tettigonia  atropunctata)  occurs  in  these  local- 
ities and  sometimes  does  considerable  injury  in  the  early  part  of  the 
season. 

The  principal  injury  occasioned  by  this  insect  is  due  to  the  extraction 
of  the  plant  juices.  These  are  sucked  out  by  means  of  a  sharp  beak  or 
proboscis,  which  is  inserted  into  the  plant  tissues.  The  first  evidence 
of  injury  is  a  pale  spot  around  the  point  of  puncture.  As  these  spots 
become  more  numerous  the  leaf  assumes  a  variegated  appearance,  due 
to  these  pale  spots,  which  indicates  a  lack  of  chlorophyll  or  green  mat- 
ter. As  the  injury  increases  the  leaf  becomes  pale  yellow  in  color,  and 
later  dries  up  and  falls  to  the  ground.  The  leaves  first  attacked,  and 
those  which  suffer  most  throughout  the  season,  are  about  the  crown  of 


112  UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 

the  vine.  In  the  vines  thus  infested,  all  the  leaves  within  a  radius  of 
a  foot  or  two  from  the  center  of  the  vine  have  dried  up  and  many  have 
fallen  off  by  the  end  of  June  or  July,  thus  exposing  the  fruit.  This 
early  loss  of  foliage  prevents  the  berries  from  maturing  properly.  The 
sugar  content  of  the  grape  is  much  reduced,  and  in  table  varieties  the 
characteristic  coloring,  which  is  important,  is  not  attained.  In  addition, 
the  fruit  is  badly  soiled  by  the  excrement  of  the  hoppers — which  serves 
to  hold  dust  and  dirt  or  offers  suitable  conditions  for  the  growth  of 
fungi — and  often  this  covers  the  leaves  so  thoroughly  as  to  interfere 
with  respiration.  The  loss  of  leaves,  or  any  interference  with  their 
normal  functions,  also  prevents  the  proper  ripening  of  the  canes  for  the 
next  year's  wood,  and  thus  the  vine  may  require  a  year  or  more  to 
recover  from  severe  cases  of  hopper  injury. 

This  insect  is  not  more  than  a  tenth  of  an  inch  long  and  of  a  pale 
yellow  color,  prettily  marked  with  irregular  red  markings. 
They  are  usually  found  on  the  under  side  of  the  leaves, 
and  if  these  are  turned  over  carefully  the  insects  may  be 
seen.  They  are  very  readily  disturbed,  and  often  emerge 
from  a  vine  in  swarms,  so  that  they  are  not  likely  to  be 
mistaken  for  any  other  insect  pest  of  the  vineyard. 

Life  History. — The  life  history  of  this  insect  as  it  has 
FIG.  3.  The      been  worked  out  in  this  State  during  the  past  year  is, 

grape  leaf-  . 

hopper.          briefly,  as  follows: 

Hoppers  which  have  reached  full  growth  on  the  vine  during 
the  fall  or  late  summer  remain  in  the  vineyard  or  vicinity  during 
the  winter  season.  During  the  colder  days  they  are  more  or 
less  dormant  and  will  be  found  hiding  under  the  leaves,  or  other 
rubbish  in  the  vineyard,  or  sheltered  in  the  vegetation  along  the 
bordering  fences  or  roadsides. 

During  the  warmer  days  of  winter  they  become  fairly  active  and  will 
be  found  feeding  on  whatever  vegetation  happens  to  be  growing  among 
the  vines  or  in  the  vicinity. 

As  soon  as  the  vines  come  into  leaf  in  the  spring,  they  leave  their 
more  varied  food-plants  of  winter  and  attack  the  vine  exclusively. 
After  feeding  upon  the  grape  foliage  for  about  a  month,  egg-laying 
begins.  This  in  the  Lodi  section  during  the  past  season  was  about  May 
first.  The  eggs  are  laid  just  beneath  the  epidermis,  on  the  lower  side 
of  the  leaf,  rarely  on  the  upper  surface.  They  may  be  distributed  any- 
where over  the  surface  and  are  most  difficult  to  see  unless  one  is  famil- 
iar with  their  appearance.  We  have  counted  more  than  seven  hundred 
of  these  eggs  in  a  single  leaf.  One  hopper  will  lay,  on  an  average, 
seventy-five  to  one  hundred  eggs,  during  a  period  of  from  one  to  two 
months.  The  eggs  from  these  over-wintering  hoppers  require  about 


BULLETIN  192.  INSECTS   INJURIOUS   TO   THE   VINE.  113 

twenty  days  to  hatch.  Then  the  young  or  nymph  appears  and  begins 
at  once  to  feed  upon  the  leaves.  It  is  a  very  small  creature,  white  in 
color,  with  conspicuous  red  eyes.  After  feeding  for  a  few  days  it 
molts  or  sheds  its  skin.  Altogether  it  molts  five  times,  requiring  a 
period  of  from  seventeen  to  twenty  days  before  the  last  molt,  when  the 
full-fledged  winged  hopper  is  produced! 

After  feeding  for  a  couple  of  weeks  as  an  adult  hopper,  pairing  begins 
and  a  week  later  another  set  of  eggs  is  deposited.  These  require  but 
from  eight  to  twelve  days  to  hatch,  a  shorter  period  than  the  first  lot 
required,  probably  on  account  of  the  higher  temperature  later  in  the 
summer.  Thus  the  life  cycles  are  repeated.  Nymphs  arising  from  the 
eggs  laid  by  the  over-wintering  hoppers  began  appearing  about  the 
middle  of  May,  and  those  from  the  following  brood  about  the  middle 
of  July,  making  two  broods  during  the  season. 

CONTROL    MEASURES. 

Farm  Practices. — Since  the  over-wintering  hoppers  are  sheltered 
in  large  numbers  by  the  leaves  which  are  blown  together  in  bunches 
in  the  vineyard,  and  other  rubbish  along  the  borders,  clean  culti- 
vation will  help  to  reduce  their  numbers.  The  hoppers  depend 
for  food  upon  what  they  can  obtain  in  the  vineyard  or  vicinity,  and  if 
the  weeds  and  other  vegetation  are  kept  down  many  will  starve  or  be 
obliged  to  go  elsewhere  for  food.  When  the  vineyard  is  plowed  in  early 
spring  before  the  vines  come  into  foliage,  the  hoppers  will  all  leave  the 
vineyard  and  feed  upon  the  nearest  available  vegetation,  which  is 
usually  about  the  borders.  If  these  borders  and  roadsides  could  be 
kept  free  and  a  general  movement  for  clean  culture  inaugurated  in  a 
neighborhood,  it  might  do  much  to  prevent  the  hoppers  from  becoming 
excessive,  but  because  of  the  possibility  of  extensive  migrations  in  the 
spring  the  work  of  any  individual  grower  might  be  of  little  avail, 
though  such  migrations  did  not  occur  at  Lodi  the  present  season  and 
individual  work  would  undoubtedly  have  been  useful. 

The  Hopper  Cage. — So  far  as  the  work  has  progressed  this  year  the 
most  satisfactory  method  of  control  is  in  the  use  of  a  hopper  cage  to  be 
used  in  the  early  spring  when  the  young  shoots  of  the  vine  are  about 
four  or  five  inches  long.  This  is  to  be  supplemented,  if  necessary,  by 
spraying  for  the  first  brood  of  nymphs  early  in  June. 

The  hopper  cage  (Fig.  4)  consists  of  a  frame  work  of  laths  over  which 
is  tacked  a  double  layer  of  mosquito  wire  netting  or  a  single  20-mesh 
wire  screen.  The  bottom  consists  of  a  shallow  pan  or  tray  made  by 
turning  up  about  an  inch  of  the  edges  of  a  sheet  of  light  galvanized  iron. 
One  entire  side  of  the  cage  is  left  open,  and  there  is  a  V-shaped  opening 
in  the  tray  at  the  bottom  which  allows  the  cage  to  be  pushed  over  the 
2— BUL.  192 


114  UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 

vine.  The  base  of  the  V-shaped  opening  in  the*  bottom  is  padded  with 
leather  and  the  vine  is  bumped  and  the  hoppers  jarred  oft',  at  the  same 
time  that  the  cage  is  being  swung  into  position.  The  sides  of  the  cage 
and  the  tray  at  the  bottom  are  smeared  with  crude  oil,  and  the  hoppers 
as  they  are  jarred  off  are  caught  in  the  oil. 

If  there  is  a  breeze  blowing  the  cage  can  be  operated  with  the  open 
side  facing  the  wind  and  practically  no  hoppers  will  escape.  If,  how- 
ever, the  day  is  calm  and  warm  and  the  hoppers  are  particularly  active 


FIG.  4.    The  hopper  cage. 

a  curtain  can  readily  be  dropped  over  the  open  side  as  the  cage  is  pushed, 
onto  the  vine,  and  it  will  prevent  any  from  escaping. 

The  V-shaped  opening  which  might  allow  hoppers  to  drop  to  the 
ground  in  front  of  the  vine  can  be  covered  with  canvas,  as  follows: 
Take  two  pieces  of  canvas  about  the  shape  of  the  opening  and  a  little 
wider.  Double  this  once  on  itself  and  between  the  two  layers  sew  in 
pieces  of  three-fourths  inch  rubber  tubing  transversely.  These  are  then 
firmly  tacked  on  the  sides  of  the  opening  as  shown  in  the  figure.  This 
will  allow  the  cage  to  be  pushed  in  on  the  vine  and  the  flexibility  of 
the  tubing  will  bring  the  canvas  immediately  into  position  again. 
This,  with  the  curtain  in  front,  shuts  off  all  possibility  of  escape. 

This  device  can  be  used  to  advantage  only  when  the  vines  are  headed 


BULLETIN  192.  INSECTS  INJURIOUS  TO  THE  VINE.  115 

some  little  distance  from  the  ground  so  that  the  bottom  of  the  cage  can 
be  pushed  under  them.  While  it  is  generally  conceded  that  this  is  the 
proper  way  to  prune  most  vines,  there  are  still  some  vineyards  in  the 
State  where  the  vines  have  been  headed  immediately  at  the  ground,  and 
some  others  have  been  given  this  form  by  frost.  For  such  vines,  if  the 
cage  is  to  be  used  at  all,  it  must  be  used  with  no  bottom,  or,  at  least,  a 
less  complete  one  than  the  cage  described. 

This  cage  should  be  used  in  the  early  spring  when  the  shoots  are  not 
more  than  four  or  five  inches  long.  At  this  time  all  the  hoppers  will 
be  found  on  the  vines  and  they  have  not  yet  laid  any  eggs.  The  cage 
need  not  be  much  larger  than  the  diameter  of  the  vines  after  pruning. 
The  size  of  the  cage  and  the  opening  at  the  bottom  should  be  made 
according  to  the  size  of  the  vines  to  be  treated. 

This  cage  can  be  used  at  comparatively  little  expense — there  being 
practically  no  cost  for  materials — as  the  chief  outlay  is  the  time  of  the 
men  employed  in  handling  it.  Such  a  cage  can  be  manipulated  by  a 
couple  of  men,  and  for  small  vines,  four  or  five  years  old  or  under,  it 
may  be  handled  by  only  one.  Four  or  five  acres  can  be  covered  in  a 
day  and  the  oil  used  can  be  bought  for  a  trifle. 

If  this  cage  is  conscientiously  used  it  will  catch  from  85  to  95  per 
cent  of  the  hoppers,  and  this,  at  a  time  before  any  eggs  have  been  laid, 
ought  to  control  the  situation  for  the  season.  No  migrations  were 
observed  during  the  past  season  until  about  the  middle  of  July,  and  if 
the  vines  have  not  already  been  injured,  they  will  not  suffer  much  loss 
from  an  attack  at  this  time  or  later. 

Spraying. — If  for  any  reason  the  above  method  has  not  been  used,  or 
satisfactorily  done,  the  next  most  successful  method  is  to  spray  for  the 
first  brood  of  nymphs  or  young.  The  time  for  doing  this  during  the 
past  season  at  Lodi  was  about  the  first  of  June,  but  the  date  will  vary 
with  the  season  and  location.  The  sprays  which  were  found  to  be 
satisfactory  were  the  whale-oil  soap  solution  and  the  resin  spray.  The 
materials  used  in  these  sprays  were  one  pound  of  soap  or  resin  to  fifteen 
gallons  of  water.  About  one-fourth  of  a  pound  of  ordinary  lye  should 
be  used  to  each  pound  of  resin  to  make  it  dissolve  thoroughly. 

An  "upper  shot"  spray  should  be  used,  and  the  best  type  of  nozzle 
for  this  is  an  eddy  chamber  Vermorel,  where  the  liquid  is  turned  at 
right  angles  in  the  chamber.  This  style  does  away  with  anything  to 
catch  among  the  canes,  and  such  a  nozzle  may  be  poked  anywhere 
through  the  vine  without  being  caught. 

Thoroughness  is  most  important  here,  since  the  spray  will  kill  no 
more  than  it  hits.  The  under  side  of  every  leaf  must  be  wet  with  the 
solution.  If  this  is  done  by  the  first  of  June  when  the  growth  is  small, 
it  is  not  an  exceedingly  difficult  task.  This  spraying  is  expected  to  kill 


116 


UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 


the  nymphs  only.  It  will,  of  course,  kill  a  few  adults,  but  the  number 
of  these  will  be  very  small.  In  addition  to  the  adults  which  escape, 
there  are  eggs  at  this  time  which  the  spray  will  not  prevent  from 
hatching.  While  this  means  of  control  will  kill  a  very  satisfactory 
percentage  of  the  nymphs,  many  adults  will  escape,  and  the  eggs  will 
be  left  to  hatch  later. 

The  advantage  of  the  cage  method  is  that  it  is  more  thorough  and 
effective.  The  hoppers  are  attacked  at  a  critical  time;  i.  e.,  when  all 
adults  are  in  the  vineyard;  and  as  they  have  not  commenced  to  breed 
or  to  lay  eggs  the  work  is  effective  in  greatly  diminishing  the  numbers 
of  succeeding  generations. 


THE  IMPORTED  GRAPE-ROOT  WORM. 

(Adoxus  vitis  Fourcroy.) 

This  pest  of  the  vine  has  been  reported  from  different  parts  of  the 
State  for  a  number  of  years,  but  until  a  year  or  two  ago  it  was  unknown 

as  a  root  feeder.     In 
our  literature    it  has 

/  commonly  gone  by  the 

name   of   flea   beetle, 
and     probably    most 


I, 


growers  know  it  by 
that  name.  It  is  not, 
however,  a  flea  beetle 
at  all,  since  it  neither 
jumps  as  indicated  by 
the  name,  nor  is  its 
life  history  similar  to 
that  of  a  flea  beetle. 

It  was  called  by 
Matthew  Cooke,  in  his 
book  entitled  "Inju- 
rious Insects  of  the 
Orchard  and  Vine- 
yard," the  "  Imported 
Grape  Flea  Beetle." 
Since,  however,  it  is 
a  root  beetle  rather  than  a  flea  beetle  and  is  probably  an  imported 
insect,  and  in  its  life  history  is  almost  identical  with  the  grape-root 
worm  of  the  Eastern  States,  we  propose  giving  it  the  common  name  of 
Imported  Grape-Root  Worm. 


FIG.  5.    Adult  of  the  grape-root  worm. 


BULLETIN  192. 


INSECTS    INJURIOUS    TO    THE   VINE. 


117 


This  insect  has  done  considerable  damage  in  this  State  within  the 
past  two  or  three  years,  and  promises  to  be  a  serious  enemy  of  the  vine- 
yardists  unless  held  in  check.  The  grape-root  worm  of  the  Eastern 
States,  identical  in  all  important  respects  with  this  one,  is  one  of  the 
most  serious  pests  the  grape-grower  in  that  region  has  to  fight. 

The  insect  injures  both  the  roots  and  the  growing  parts  of  the  vine 
above  ground.  It  is  a  small  beetle,  about  one-fifth  of  an  inch  long,  and 
either  black  or  brown  in  color.  There  is  no  mistaking  its  identity  from 


FIG.  6.    Leaf  eaten  by  root  beetle. 

the  way  it  eats  out  chain-like  strips  from  the  leaf,  or  gouges  out  similar 
strips  on  the  shoots  and  other  growing  parts. 

Life  History. — The  adult  beetle  appears  in  May,  having  emerged  from 
the  ground  where  it  has  been  since  the  previous  year,  and  where  it  has 
passed  through  the  larval  and  pupal  stages.  It  begins  at  once  to  feed 
upon  the  leaves,  eating  out  narrow  slits  about  one-twentieth  of  an 
inch  wide  and  from  one-fourth  to  three-fourths  of  an  inch  long.  It 
attacks  the  shoots,  petioles,  pedicels,  and  to  a  less  extent  the  berry 
itself  in  the  same  way. 

After  feeding  for  a  couple  of  weeks,  egg-laying  begins.  The  eggs  are 
deposited  on  the  inner  bark,  or  in  crevices,  usually  beneath  two  or 
three  layers  of  the  old  bark.  They  are  laid  in  clusters  of  from  four  or 


118  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT   STATION. 

five  to  twenty-five  or  thirty.     Hatching  occurs  in  from  eight  to  twelve 

days,  when  the  young  larva  appears  and  crawls,  or  possibly  drops,  to 

the  ground  and  makes  its  way  to  the  roots. 

After  having  burrowed  its  way  through  the  ground  to  the  roots  it 

begins  feeding,  probably  mostly  on  the  smaller   roots  at  first,    later 

attacking  the  larger  ones  and  eat- 
ing out  strips  of  the  bark.  This 
feeding  continues  until  winter, 
when  the  larva  becomes  dormant, 
finally  changing  to  the  pupa  in  the 
following  spring.  Pupation  took 
place  this  year  during  the  last  of 
April,  and  continued  well  into  June. 
The  first  beetles  emerged  about  the 
first  of  May. 

The  most  serious  injury  to  the 
vine  is  due  to  the  work  of  the  larvae 

FIG.  7.    Imported  grape-root  worm.  ,1  ,1  n  i 

on  the  roots,  the  small  roots  being 

eaten  off  entirely,  thus  preventing  the  plant  foods,  taken  up  directly 
by  the  root  hairs,  from  reaching  the  growing  parts  of  the  vine.  The 
larger  roots  are  injured  by  having  strips  of  the  bark  eaten  off,  in  bad 
cases  of  injury  scarcely  any  of  the  bark  being  left.  Vines  thus  affected 
show  a  stunted  condition,  the  canes  failing  to  attain  a  normal  growth, 
and  in  severe  cases  the  vines  may  be  killed  outright. 

Con trnl  Measures. — Since  the  insect  comes  to  the  surface  and  feeds 
upon  the  leaves  and  other  growing  parts  of  the  vine  an  opportunity  is 
offered  for  fighting  it  in  this  stage.  The  beetles  are  very  readily  jarred 
from  the  vine  and  may  be  captured  if  something  is  placed  under  the 
vines  in  which  they  can  be  caught. 

The  hopper  cage,  described  on  page  114,  checked  the  development  of 
the  beetles  in  a  vineyard  near  Lodi  during  the  past  season.  This 
means  has  the  advantage  of  capturing  the  hoppers  also,  which  are  more 
than  likely  to  be  present,  at  the  same  time.  The  fact  that  the  beetles 
keep  emerging  from  the  ground  for  a  month  or  so  may  make  more  than 
one  operation  necessary.  Fortunately,  however,  the  beetles  are  usually 
confined  to  a  limited  area  of  the  vineyard,  so  that  it  is  not  necessary  to 
go  over  a  large  area.  When  the  beetles  alone  are  to  be  caught,  simply 
the  tray  on  the  bottom  of  the  cage  can  be  used.  Handles  may  be 
attached  directly  to  the  tray  for  convenience  in  manipulating. 

These  beetles  may  also  be  fairly  well  controlled  by  an  arsenical 
spray.  They  are  rather  resistant  to  poisons  and  a  strong  dose  must  be 
used.  We  obtained  fairly  satisfactory  results  by  using  lead  arsenate 
in  the  ratio  of  five  pounds  to  fifty  gallons  of  water.  Paris  green  may 


BULLETIN  192. 


INSECTS   INJURIOUS   TO   THE  VINE. 


119 


be  used  and  the  ratio  of  at  least  one  pound  to  one  hundred  gallons  of 
water  is  required.  This  spraying  should  be  done  as  soon  as  the  first 
beetles  make  their  appearance  in  the  spring. 

Since  the  pupae  are  within  four  to  eight  inches  of  the  surface  much 
good  can  be  done  by  thoroughly  stirring  the  ground  within  a  radius  of 
two  or  three  feet  about  the  vine  for  a  depth  of  six  inches  or  more.  If 
this  can  be  done  at  the  proper  time  when  they  are  in  the  pupal  stage 
it  will  no  doubt  destroy  many. 

It  has  been  suggested  and  some  experiments  seem  to  prove  that  if 
the  land  is  left  uncultivated  about  the  base  of  the  vine,  the  beetles  will 
be  unable  to  break  through  the  crust  at  the  surface.  We  have  not  had 
opportunity  to  demonstrate  this  point.  If  successful  it  must  depend 
largely  upon  a  type  of  soil  that  will  form  a  hard,  impenetrable  layer  at 
the  surface. 


HAWK  MOTH  LARVAE. 

These  larvae  are  occasionally  met  with  over  large  areas  every  year  in 
California,  and  in  certain  restricted  areas  they  sometimes  become 
exceedingly  abundant  and  may  completely  defoliate  a  vineyard.  The 
worst  case  that  has  come  to  our  notice  this  ye^ir  was  on  a  vineyard 
belonging  to  the  California  Wine  Association  near  Reedley. 


FIG.  8.    Showing  one  vine  in  a  75-acre  vineyard  defoliated  by  Hawk  Moth  larvae. 


120 


UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 


Here  seventy-five  acres  of  vines  were  completely  stripped  of  their 
foliage  and  scarcely  an  entire  leaf  was  left  on  the  area.  As  many  as 
one  hundred  and  fifty  full-grown  larvae  were  counted  on  a  single  vine. 

In  this  case  the  owners  were  not  aware  of 
the  extent  of  the  danger  until  the  worms 
had  become  nearly  full  grown,  and  most  of 
the  damage  done.  At  this  time,  however 
a  gang  of  about  two  hundred  men  was  set 
to  work  picking  them  off  the  vines,  and 
worms  were  carried  away  by  the  cartloads 
'and  burned.  The  species  concerned  here 
was  the  Achemon  Sphinx  (Philampeles 
achemon  Drury),  which  is  the  most  com- 
mon species  attacking  the  grapevine  in 
the  State. 

These  caterpillars  may  be  found  on  the 
vines  late  in  May,  and  during  the  larger 
part  of  June.  The  larva?  are  green  in  color, 
like  the  leaf,  and  are  therefore  not  readily 
distinguishable  when  they  are  small.  They 
soon  increase  in  size,  however,  and  their 
work  on  the  leaves  becomes  noticeable. 
While  small,  these  larvae  may  be  distin- 
guished by  a  large  horn  on  the  posterior 
end  of  the  body,  but  this  is  lost  during  a  molt  before  they  are  quite 
full  grown. 

Life  History. — These  insects  hibernate  in  the  pupa  or  chrysalis  stage, 
and  while  in  the  ground  may  be  distinguished  as  large  cylindrical 
objects  of  a  dark  brown  color  (Fig.  10).  About  the  middle  of  May  or 
thereabouts  they  emerge  from  these  chrysalids  in  the  ground  as  large 
and  handsome  moths  (Fig.  11).  These  are  the  common  moths  that 
poise  over  flowers  at  dusk.  They  are  particularly  attracted  by 
petunias,  and  it  has  been  suggested  that  they  might  be  captured  in 
large  numbers  about  these  flowers. 

The  eggs  are  laid  on  the  vine,  and  the  larvae,  upon  hatching,  begin 
immediately  to  feed  upon  the  grape  foliage.  Since  they  are  voracious 
feeders  and  grow  to  a  very  large  size,  three  inches  long  or  more,  they 
consume  an  enormous  quantity  of  leaves.  This  year  most  of  the  larvae 
were  mature  by  the  twentieth  of  June.  When  mature  they  repair  to 
the  ground,  where  they  pupate.  In  the  vineyard  already  mentioned, 
there  appeared  a  second  brood  of  caterpillars  during  the  middle  of 
July.  None  of  these  reached  their  full  growth,  dying  from  some 
unknown  cause  while  they  were  but  an  inch  and  a  half  long.  They 


FIG.  9.     Hawk    Moth    larva. 
(Philampeles  achemon  Drury.) 


BULLETIN  192. 


INSECTS    INJURIOUS    TO    THE   VINE. 


121 


had  all  disappeared  when  we  visited  the  vineyard  on  August  the  first, 
and  according  to  the  owners  they  simply  dried  up.  It  was  probably 
due  to  a  fungous 
disease  which  often 
destroys  these  cat- 
erpillars in  great 
numbers.  We  also 
found  these  cater- 
pillars in  the  vine- 
yards about  Lodi  in 
June  and  August, 
indicating  that 
there  are  two 
broods  in  a  season. 

Control  Measures. 

Where    there     are 

but     occasional 

specimens    of   this 

insect  found  in  the 

vineyard,     the 

cheapest  and  most 

practical  way  is  to 

pick   them   off   by 

hand.  Where  there 

are  immense  num- 
bers   of  them,   as  in  the  case  mentioned  at    Reedley,    hand   picking 

becomes  a  laborious  task.     In  the  latter  case  a  thorough  spraying  with 

a  strong  arsenical 
spray  applied  just 
at  the  time  they 
are  hatching,  will 
check  them  before' 
they  can  do  a  great 
deal  of  harm. 

If  the  adult 
moths  are  particu- 
larly attracted  by 
the  petunias,  as 
seems  to  be  the 
case,  '  a  means  of 
capturing  them  in 
this  stage  may  be 

found  in  poisoning  the  flowers  thoroughly  with  some  soluble  poison  or 

by  catching  them  in  traps.     The  effectiveness  of  these  methods  will 


FIG.  10.    Chrysalids  of  a  Hawk  Moth  (Philampeles  achemon  Drury). 


FIG.  11.    Hawk  moth  (Philampeles  achemon  Drury). 


122 


UNIVERSITY  OF   CALIFORNIA — EXPERIMENT   STATION. 


depend  upon  whether  many  of  the  eggs  are  deposited  before  they  fly 
about  much.  While  numbers  of  moths  may  be  caught  in  this  way, 
it  is  doubtful  if  it  will  ever  prove  of  very  great  practical  value. 


GRASSHOPPERS. 

These  insects  do  a  great  deal  of  injury  to  vines  every  year  in  some 
parts  of  the  State.  This  year  they  have  been  abundant  everywhere 
and  considerable  damage  has  resulted.*  In  a  vineyard  twelve  miles 
east  of  Fresno  forty  or  fifty  acres  of  vines  were  completely  defoliated. 
These  insects  are  generally  most  troublesome  in  new  vineyard  sections 
or  localities  surrounded  by  large  areas  of  uncultivated  land. 


FIG.  12.    Vineyard  defoliated  by  grasshoppers. 

Life  History, — The  eggs  of  the  grasshoppers  are  laid  in  the  ground 
in  the  late  summer  or  fall,  and  a  decided  preference  is  shown  for  uncul- 
tivated land.  These  eggs  are  laid  in  capsules  containing  a  large  num- 
ber, and  are  protected  by  a  frothy  or  gummy  substance  which  prevents 
them  from  being  affected  by  unusual  weather  conditions.  The  eggs 
remain  in  the  ground  during  the  winter  and  hatch 'the  folio  wing  spring. 
The  young  grasshopper  is  similar  in  appearance  to  the  adult,  except 
that  the  wings  are  lacking,  but  these  are  gradually  acquired  with  molt- 
ing. There  is  usually  but  a  single  generation,  though  in  some  parts  of 
the  State  there  are  probably  two. 


BULLETIN  192. 


INSECTS   INJURIOUS   TO   THE   VINE. 


123 


FIG.  13.     Valley  grasshopper  ((Edaleonotus  enigma). 


Control  Measures. — Grass- 
hoppers may  be  controlled 
by  poisoned  bait,  by  spray- 
ing heavily  a  few  rows  along 
the  border  of  a  field,  by  the 
hopper  dozer,  by  burning 
waste  feeding  areas,  and  by 
the  introduction  of  turkeys. 
Various  combinations  of  two 
or  more  of  these  measures 
may  be  used  to  fit  particular 
cases.  Of  the  methods  used 

to  protect  vineyards,  poisoned  bait  is  probably  the  most  common.     This 
consists  of  bran  and  molasses  or  other  sweet  substance  poisoned  with 

arsenic  and  distributed  in 
handfuls  about  the  vine.  The 
proportions  are  as  follows: 
forty  pounds  of  bran,  two  gal- 
lons of  cheap  molasses,  and 
five  pounds  of  arsenic.  Cheap 
glycerine  may  be  used  to  pre- 
vent the  mixture  from  drying. 
If  the  grasshoppers  are  enter- 
ing in  well-defined  swarms 
and  caught  on  the  first  few 
rows  they  may  be  killed  by 
heavily  poisoning  a  few  rows  on  the  side  at  which  they  are  entering. 
Some  growers  find  turkeys  to  be  the  most  successful  destroyers,  and  if 
the  hoppers  are  not  too  abundant,  this  method  is  probably  as  good  as 
any,  particularly  at  a  time  when  the  hoppers  are  still  small. 


FIG.  14.    Differential  grasshopper  (Melanoplus 
differentialis).    Young. 


FIG.  15.    Differential  grasshopper  (Menanoplus  differentialis).    Adult. 


124 


UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 


Those  who  have  been  most  successful  with  turkeys  go  about  using 
them  in  a  systematic  way.  They  turn  in  a  band  of  them  early  in  the 
morning  and  let  them  feed  for  a  couple  of  hours,  then  drive  them  into 
a  cool  barn  where  they  remain  through  the  heat  of  the  day.  In  the 
evening  they  are  again  turned  into  the  vineyard  for  two  or  three  hours 
and  again  confined  in  an  inclosure,  so  that  they  obtain  a  straight  grass- 
hopper diet  supplemented  by  gravel,  to  which  they  have  access  while 
not  in  the  vineyard. 

When  vineyards  adjoin,  or  are  near,  large  uncultivated  tracts,  where 
the  grasshoppers  hatch  out  in  large  numbers,  it  is  best  to  look  beyond 
the  vineyard  in  planning  the  control.  This  may  mean  more  or  less 
organized  effort  in  burning  off  or  plowing  such  uncultivated  lands. 
For  a  full  account  of  this  and  other  methods  of  grasshopper  control 
the  reader  is  referred  to  Bulletins  Nos.  142  and  170  of  this  Station. 


CUT  WORMS  AND  ARMY  WORMS. 

These  are  the  larvae  of  Noctuid  moths,  which  often  become  abundant 
over  limited  areas  and  do  much  damage  to  vines. 

Cut  worms  and  Army  worms  are  terms  applied  to  the  same  insects  in 

California.  In  ordinary  years  they 
are  not  present  in  sufficient  numbers 
to  cause  much  concern,  and  in  such 
years  they  are  known  simply  as  cut 
worms.  When  all  conditions  are 
favorable,  however,  certain  species 
develop  in  enormous  numbers  and 
having  exhausted  the  food  supply 
where  they  breed,  they  begin  to 
migrate  or  march,  commonly  in  a 
definite  direction,  as  an  army  in 
search  of  new  food.  When  they  thus 
appear  in  such  large  numbers  and 
take  on  the  migrating  habit  they  are 
called  army  worms. 

Some  of  the  caterpillars  have  the 
habit  of  climbing  up  vines  and 
trees  and  eating  off  the  buds  in 
the  early  spring.  These  are  called 
climbing  cut  worms.  Others  remain  at  or  near  the  surface  of  the 
ground  and  feed  by  cutting  off  the  plants  at  this  point.  They  are  more 
commonly  found  in  the  grass  lands,  but  very  frequently  attack  culti- 


FIG.  16.  Army  worm  (Heliophila  uni- 
puncta).  The  species  that  was  abundant 
at  Lodi  this  year. 


BULLETIN  192. 


INSECTS    INJURIOUS    TO    THE   VINE. 


125 


vated  crops,  particularly  on  land  that  was  in  grass  the  previous  year. 
It  is  the  two  former — the  climbing  cut  worms  and  army  worms  — that 
chiefly  concern  growers  of  vines. 

The  climbing  cut  worms  appear  in  the  early  spring  and  eat  off  the 
expanding  buds.  They  also  feed  upon  the  young  leaves  as  they  appear, 
but  an  early  attack  on  the  swelling  buds  is  when  the  most  serious 
damage  is  done,  because  the  removal  of  the  principal  bud  destroys  the 
fruit  and  the  later  buds  usually  produce  sterile  shoots.  The  two 
commonest  species  concerned  here  are  Paragrotis  meswria  Harris  and 
Peridroma  margaritosa  sauci  Hubn. 

The  life  history  of  all  the  species  of  this  group  is  much  the  same, 


FIG    17.    Moths  of  cut  worms. 

.and  they  may  be  discussed  together.  The  majority  spend  the  winter 
as  a  partly  grown  larva.  In  the  spring  they  again  become  active  and 
begin  to  feed  after  being  more  or  less  dormant  during  the  winter.  If 
they  are  the  climbing  species  they  may  be  found  attacking  the  buds  or 
young  leaves  of  the  vine.  When  they  become  full-grown  larvae  they  go 
to  the  ground,  where  they  change  to  pupae.  After  two  or  three  weeks 
in  this  stage  the  adult  moth  appears.  These  are  usually  dark  colored 
(Fig.  17),  and  because  they  fly  about  at  night  are  seldom  seen. 

The  eggs  are  laid  mostly  on  the  stems  of  grasses  near  the  ground. 
The  larvae  hatching  from  these  feed  at  or  near  the  ground,  and  since 
they  work  mostly  at  night  are  not  readily  seen  in  their  concealed  situa- 
tions during  the  day.  There  being  plenty  of  vegetation  at  this  season 
also  they  do  not  interfere  seriously  with  the  crop.  By  fall  they  become 


126  UNIVERSITY  OP   CALIFORNIA EXPERIMENT   STATION. 

partly  grown  and  spend  the  winter  in  a  more  or  less  dormant  condi- 
tion. There  are  generally  two  broods  of  the  worms  in  California  and 
in  some  cases  probably  three.  Any  one  of  several  species,  however,  may 
increase  to  immense  numbers,  and  they  are  then  called  army  worms. 

They  appear  in  large  numbers  as  army  worms,  generally  with  the 
second  brood  in  midsummer.  During  the  past  year  in  the  vicinity  of 
Lodi  there  was  a  distinct  outbreak  of  army  worms  appearing  simulta- 
neously in  a  dozen  or  more  different  places.  In  nearly  every  case  these 
came  from  grain  fields  in  which  they  bred,  and  because  of  the  large 
numbers  and  scarcity  of  food  were  forced  to  migrate,  and  as  a  result, 
a  number  of  vineyards  were  threatened  with  defoliation.  These  grain 
fields  or  breeding  places  become  pretty  well  dried  up  by  August,  and 
furnish  very  little  succulent  growth  for  the  voracious  army  worm. 

The  worms  appeared  this  year  during  the  first  week  in  August.  They 
had  been  feeding  for  a  week  or  two  in  the  grain  fields,  since  some  were 
nearly  full  grown,  but  had  not  been  observed  to  migrate  until  the  date 
mentioned.  In  one  of  these  grain  fields  a  contagious  bacterial  disease 
killed  them  off  by  the  thousands,  and  very  effectively  checked  their 
progress.  Portions  of  a  number  of  young  vineyards  were  defoliated 
before  their  presence  was  realized.  The  species  concerned  here  was  the 
true  army  worm  of  the  Eastern  States,  which  bears  the  scientific  name 
of  Heliophila  unipuncta.  In  bearing  vineyards,  besides  eating  off  the 
leaves,  these  worms  have  the  pernicious  habit  of  cutting  off  the  stems 
of  the  clusters  of  fruit,  which  drop  to  the  ground  and  dry  up.  In  a 
portion  of  a  bearing  vineyard  near  Lodi,  where  these  pests  were  present, 
this  unripe  fruit  was  picked  up,  while  still  fresh,  by  the  basketfuls  and 
made  into  jelly. 

These  caterpillars  are  mostly  dull-colored  worms  from  one  to  two 
inches  long,  with  longitudinal  strips  of  black,  gray  and  yellow  or  red- 
dish brown.  There  is  considerable  variation  in  color  in  the  same 
species,  some  being  much  darker  in  color.  Generally  the  midsummer 
brood  from  which  the  army  worms  arise  are  darker  colored  than  the 
spring  brood.  The  one  present  in  Lodi  and  vicinity  this  year  (see  Fig. 
16)  had  a  broad  black  velvety  stripe  on  the  dorsal  side.  Below  this 
was  a  stripe  of  whitish  yellow  about  one  half  the  width  of  the  former, 
with  its  center  made  up  of  broken  wavy  lines.  Below  this  was  another 
narrow  stripe  of  black  with  the  spiracles  on  the  lower  edge;  back  and  a 
little  above  each  spiracle  was  a  conspicuous  white  spot  that  on  first 
sight  would  be  taken  for  the  spiracles  themselves.  Below  this  is  another 
stripe  of  light  brown,  and  on  the  ventral  surface  a  general  color  of 
cinnamon  brown. 

Control  Measures. — The  cut  worm,  although  belonging  to  the  same 
group  as  the  army  worm,  on  account  of  the  difference  in  habits  must 
be  controlled  in  a  different  way.  Since  it  is  those  species  which  acquire 


BULLETIN  192.  INSECTS  INJURIOUS  TO  THE  VINE.  127 

the  climbing  habit  that  attack  vines,  they  require  a  different  manner 
of  treatment  from  those  which  feed  upon  plants  at  or  near  the  surface. 
Because  they  actually  devour  the  buds  of  the  vine,  the  application  of 
a  poison  spray  ought  to  be  effective.  However,  since  the  surface  on 
which  there  may  be  poison  in  the  case  of  buds  is  so  small,  one  worm 
may  destroy  most  of  the  buds  on  an  ordinary-sized  vine  before  the  dose 
eaten  will  prove  fatal.  Probably  one  of  the  best  ways  of  fighting  these 
is  to  place  poisoned  bait  around  the  base  of  the  vine.  (For  the  ingre- 
dients see  under  Grasshoppers,  page  123.)  This  will  be  eaten  by  the 
worms  in  preference  to  climbing  up  the  vines  and  destroying  the  buds. 
They  may  also  be  captured  by  means  of  traps.  Because  of  their  habit 
of  feeding  at  night  and  remaining  concealed  during  the  day,  pieces  of 
boards  may  be  placed  on  the  ground  around  the  vine  and  these  may  be 
turned  over  during  the  day  and  the  worms  killed. 

In  case  of  outbreaks  of  army  worms  the  most  important  and  success- 
ful means  of  fighting  them  is  to  keep  them  out  of  the  vineyards 
entirely.  This  can  be  successfully  done  if  they  are  discovered  in  time, 
or  if  already  in  one  portion  they  can  be  kept  from  spreading  over  the 
rest  of  the  vineyard.  They  travel  in  immense  numbers  in  a  definite 
direction,  coming  generally  from  an  adjoining  or  nearby  grain  field.  If 
a  furrow  is  plowed  along  the  side  of  the  vineyard  to  be  protected  it  will 
effectively  stop  their  progress.  This  furrow  should  be  plowed  as  deep 
as  possible,  with  the  vertical  side  next  to  the  field  to  be  protected.  It 
can  be  further  trimmed  with  a  spade,  preferably  cutting  under  slightly, 
making  a  smooth  surface,  over  which  few  if  any,  of  the  worms  will 
make  their  way.  Above  this  shoulder  fine  pulverized  earth  should 
slope  as  abruptly  upward  as  possible.  If  any  of  the  worms  succeed  in 
climbing  up  over  the  smooth  surface  made  by  the  spade  they  will  be 
pretty  sure  to  fall  back  as  they  reach  this  fine  loose  earth  in  an  attempt 
to  ascend  over  the  projecting  shoulder.  Postholes  should  be  dug. on 
the  straight  edge  of  the  furrow  every  fifteen  or  twenty  feet.  The  worms 
in  failing  to  scale  the  vertical  side  of  the  furrow  will  crawl  along  in  the 
bottom  and  fall  into  these  holes.  Here  they  may  be  killed  by  pouring 
in  a  little  crude  oil,  or  by  pouring  in  a  little  distillate  and  dropping  in 
a  match,  thus  burning  them,  or  the  holes  filled  in  and  others  dug.  They 
may  also  be  killed  in  the  furrow  by  sprinkling  them  with  kerosene  or 
by  pouring  a  strip  of  crude  oil  along  the  furrow. 

It  is  most  essential  in  fighting  army  worms  that  prompt  and  vigorous 
efforts  be  undertaken  immediately,  since  a  day's  delay  may  mean  con- 
siderable loss  and  more  difficulty  in  handling  the  situation.  Once  they 
are  in  the  vineyard  the  vines  infested  should  be  heavily  sprayed  with 
lead  arsenate  at  the  rate  of  five  pounds  to  fifty  gallons  of  water,  or 
with  paris  green  in  the  proportion  of  one  pound  to  seventy-five  or  one 
hundred  gallons  of  water.  In  addition  to  this  the  furrow  should  be 


128  UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 

plowed,  as  already  described,  beyond  the  infested  portion  to  check  their 
further  spread.  If  these  measures  are  undertaken  promptly,  what 
might  be  a  serious  loss  can  be  averted. 


FLEA  BEETLES. 

(Haltica  sps.) 

These  beetles  have  generally  been  confused  with  the  root  beetle 
already  discussed  in  this  bulletin.  In  these  beetles  the  thighs  of  the 
hind  legs  are  enlarged,  thus  enabling  the  insect  to  jump  much  in  the 
same  way  as  the  flea;  hence  the  name.  They  have  frequently  been 
reported  as  doing  damage  in  the  State,  but  during  the  past  season  we 
have  not  learned  of  any  important  injury  done  by  them.  Two  or  three 
specimens  were  taken  near  Lodi,  and  while  no  particular  effort  was 
made  to  collect  them,  this  was  all  we  obtained  during  the  season. 
Certainly  there  were  no  large  numbers  of  these  beetles  in  the  sections 
where  our  work  was  carried  on  this  past  year.  Several  growers  reported 
that  the  flea  beetle  was  doing  considerable  damage,  but  upon  investi- 
gation these  were  found  to  be  the  root  beetle.  They  are  said  to  be 
particularly  abundant  in  the  Sonoma  Valley,  but  we  did  not  have  the 
opportunity  of  visiting  the  valley  during  the  present  season.  There 
are  about  a  dozen  species  of  the  genus  Haltica  occurring  in  this  State, 
probably  the  commonest  occurring  on  the  vine  being  the  species  bimar- 
ginata.  This  species  is  not  confined  to  the  grape  alone,  and  during  the 
past  year  it  was  exceedingly  abundant  in  many  places  over  the  State 
"on  the  alder.  The  grape  flea  beetle  of  the  Eastern  States  (Haltica 
chalybia)  is  not  known  to  occur  here. 

The  flea  beetle  on  the  grape  is  commonly  of  a  bluish  color,  about  one- 
fifth  of  an  inch  in  length,  and  is  capable  of  jumping,  while  the  root 
beetle  is  either  black  or  brown  in  color  and  has  no  power  to  jump.  The 
injuries  of  these  two  beetles  are  also  readily  distinguishable.  The  flea 
beetle  eats  out  irregular  holes,  which  may  differ  much  in  size  and  shape, 
while  the  root  beetle  eats  out  narrow  strips  of  very  uniform  size  and 
shape.  They  also  present  entirely  different  life  histories. 

Life  History. — The  flea  beetle  passes  the  winter  among  leaves  or  in 
other  situations  affording  some  protection  to  the  adult  beetle,  and 
emerges  in  the  early  spring  and  feeds  upon  the  buds  of  the  vine.  These 
may  be  entirely  eaten  away  or  the  centers  gouged  out,  thus  destroying 
the  buds.  After  feeding  for  some  time  they  begin  depositing  their 
eggs,  generally  in  the  cracks  in  the  bark  or  at  the  base  of  the  buds. 
The  larvae,  after  hatching  out,  attack  the  leaves  and  eat  out  holes,  as 
already  indicated.  They  continue  to  feed  as  larvse  for  three  or  four 


BULLETIN  192.  INSECTS  INJURIOUS  TO  THE  VINE.  129 

weeks,  when  they  drop  to  the  ground,  make  a  little  cell  just  beneath 
the  surface,  and  change  to  pupae.  The  beetles  emerge  a  week  or  two 
later  and  these  feed  upon  the  leaves.  There  are  probably  two  genera- 
tions of  the  insect  each  year.  Those  we  obtained  were  taken  as  adult 
beetles  in  June,  which  were  from  eggs  laid  in  the  early  spring,  but 
whether  these  remain  until  winter  and  hibernate,  or  again  lay  eggs, 
was  not  determined. 

Control  Measures. — Since  this  insect  feeds  upon  the  foliage  both  as 
larva  and  adult,  it  may  be  controlled  by  means  of  a  poison  spray,  either 
paris  green  or  lead  arsenate.  The  beetles  are  also  easily  jarred  from  the 
vines  and  the  method  described  for  capturing  the  root  beetle  can  be 
used  here. 


THE  GRAPE-LEAF  FOLDER. 

( Desmia  funeralis  Huber. ) 

This  insect  occurs  in  considerable  numbers  in  some  sections  of  the 
State  every  year,  but  the  total  injury  is  not  usually  very  great.  During 
the  past  season  the  worst  attack  that  came  to  our  notice  was  in  a  vine- 
yard near  Reedley,  where  seventy-five  .or  one  hundred  acres  of  vines 
had  a  large  number  of  their  leaves  rolled.  On  some  vines  nearly  every 
leaf  was  found  to  be  rolled  and  harboring  the  larvae  of  this  insect. 
Occasional  specimens  were  also  found  near  Lodi,  but  they  were  not 
numerous  enough  to  do  any  important  injury. 

They  may  be  easily  detected  in  a  vineyard  by  the  characteristic 
rolling  of  the  leaves.  One  edge  is  rolled  up  rather  tightly  to  about  half 
way  across  the  leaf,  making  a  tube  less  than  the  diameter  of  a  lead 
pencil,  in  which  the  larva  lives.  The  leaf  is  always  rolled  on  the  under 
side.  The  insects  feed  by  eating  off  the  free  edge  of  the  leaf  in  the  interior 
of  the  roll,  so  that  they  are  always  protected  by  the  outer  layers  of  the 
rolled  portion.  The  insect  hibernates  as  a  chrysalis,  appearing  and 
laying  eggs  upon  the  vine  in  the  spring.  The  larvae  of  the  first  brood 
appear  about  the  first  of  June.  By  the  twentieth  of  June  at  Reedley 
this  year  the  Iarva3  had  all  changed  to  pupae.  The  larva  is  a  greenish- 
white  caterpillar,  about  an  inch  long  when  full  grown.  They  wriggle 
out  of  their  nests  very  vigorously  when  disturbed  and  drop  to  the 
ground.  *Larvae  were  taken  at  Lodi  in  June  and  August,  indicating 
that  there  are  at  least  two  broods  in  a  season. 

*  The  head  and  prothoracic  shield  are  light  brown  in  color.  On  the  mesothoracic 
segment  are  two  pale-brown  spots  or  rings,  and  beyond  these  laterally  are  two  larger 
and  darker  crescent-shaped  spots.  There  is  also  a  pale  spot  on  the  same  segment  more 
ventrally  and  a  little  forward.  On  the  preceding  segment  are  two  large  irregular  pale- 
brown  spots  and  one  small  round  spot,  also  of  pale  brown.  On  the  penultimate 
segment  there  are  two  dark  crescent-shaped  spots  situated  dorsally. 

3— BUL.  192 


BULLETIN  192. 


INSECTS   INJURIOUS   TO   THE  VINE. 


131 


This  insect  occurs,  apparently,  throughout  the  United  States.     It  is 
very  common  in  the  Eastern  and  Middle  Western  States,  but  there  is 


FIG.  19.    Larva  of  grape  leaf-roller. 


a  striking  difference  in  habits  between  the  insect  there  and  what  is 
considered  the  same  species  here.     In  the  East,  the  leaf  is  simply  folded 


FIG.  20.    Moth  of  grape  leaf-roller,  enlarged. 


over  on  the  upper  surface  and  the  edges  sewed  down  by  strands  of  silk. 
There  the  larva  feeds  by  eating  off  the  upper  surface  of  the  leaf,  thus 
skeletonizing  it.  Here  the  leaf  is  very  distinctly  rolled  and  instead  of 


132  UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 

eating  off  the  upper  surface  it  feeds  on  the  free  edge.  According  to  its 
habits  in  this  State,  leaf-roller  would  be  a  more  appropriate  name  than 
leaf-folder.  Specimens  of  the  moth  sent  to  the  Bureau  of  Entomology 
at  Washington,  D.  C.,  were  identified  by  Dr.  Dyar  as  Desmia  funeralis 
Huber— the  same  species  that  occurs  in  the  Eastern  States. 

The  moth  is  nearly  an  inch  across  the  expanded  wings,  and  is  black 
with  white  markings.  There  are  two  white  spots  on  each  wing,  those 
on  the  posterior  wings  being  larger,  and  in  some  specimens  fusing  into 
a  single  large  spot.  There  are  also  two  white  bands  across  the  abdomen, 
one  about  the  center  and  one  near  the  tip.  The  wings  are  also  bordered 
with  a  fringe  of  white,  and  the  tarsi  and  apical  half  of  the  antennae 
are  white. 

Control  Measure. — The  only  control  measure  which  is  likely  to 
prove  effective  is  to  spray  with  an  arsenical  before  the  rolling  of  the 
leaf  is  commenced,  so  that  they  may  be  obliged  to  eat  the  poison,  even 
though  they  are  within  the  rolled  portion.  If  they  are  not  too  abundant, 
hand  picking  or  simply  crushing  the  folded  portion  of  the  leaves  will 
be  the  most  practical. 


LEAF  CHAFERS. 

Under  this  head  come  the  rose  chafer,  and  other  allied  species,  which 
often  attack  the  leaves  of  the  grapevine.  The  true  rose  chafer,  which 
often  does  much  injury  to  vines  in  the  Eastern  States,  as  far  as  we  are 
aware,  does  not  occur  in  California. 

A  species  which  was  very  abundant  in  the  neighborhood  of  Florin 
during  the  past  season  was  Serica  mixta  Lee.  This  insect  was  not 
restricted  in  its  feeding,  however,  to  the  vine,  but  attacked  a  great 
variety  of  plants.  Hoplia  sackonii  has  also  been  taken  in  large  num- 
bers on  vines  at  Fresno. 

The  life  history  of  the  rose  chafer  has  been  carefully  studied,  and  the 
life  history  of  these  allied  species  may  be  much  the  same.  The  younger 
stages  of  these  insects  are  passed  in  the  ground,  where  the  larvae  feed 
upon  the  roots  of  plants,  preferably  grasses.  They  are  full  grown  by 
fall  and  in  the  spring  ascend  toward  the  surface,  where  they  change  to 
pupae.  Two  or  three  weeks  later  they  emerge  from  the  ground  as  adult 
beetles  and  attack  the  grape  and  other  plants.  A  sandy  soil  is  especially 
adapted  for  their  underground  habits.  After  feeding  as  adult  beetles 
for  two  or  three  weeks  they  deposit  their  eggs  in  the  ground  and  from 
these  the  next  generation  of  larvae  emerge  and  feed  upon  the  roots  until 
fall. 

Control  Measure. — These  insects  are  rather  difficult  to  control,  but  a 
liberal  dose  of  poison  will  check  them  if  they  are  not  present  in  great 


BULLETIN  192. 


INSECTS   INJURIOUS   TO   THE   VINE. 


133 


swarms,  as  they  sometimes  occur.     The  jarring  method  as  described  for 
the  root  beetle  will  also  prove  valuable. 

Since  these  insects  feed  in  the  larval  state  upon  the  roots  of  grasses 
growing  along  the  roadsides  or  fences  or  irrigation  ditches,  much  can  be 
done  to  prevent  an  outbreak  by  keeping  euch  places  free  from  vegetation. 


WIRE  WORMS. 

These  are  long  cylindrical  worms  with  a  dark 
brown  leathery  covering  resembling  somewhat  a 
piece  of  rusty  wire.  They  live  for  a  year  or 
more  in  the  ground,  feeding  upon  the  roots  of 
plants.  They  feed  upon  a  variety  of  plants  and 
are  not  restricted  to  grape  roots  alone.  We 
have  taken  as  many  as  fourteen  of  these  worms 
from  around  the  roots  of  a  vine  from 
a  foot  and  a  foot  and  a  half  from  the 
surface.  During  the  growing  season  of 
the  vine  when  the  vineyard  is  free 
from  vegetation  these  wire  worms  must 
feed  to  a  considerable  extent  upon  the 
roots  of  the  vine.  The  adult  is  the  well- 
known  click  or  snapping  beetle,  the  one 
most  commonly  met  with  being  about 
one-half  an  inch  long,  slender,  and  of 
a  dark  brown  or  black  color.  We  have 
seen  immense  swarms  of  these  click 
beetles  in  a  vineyard  near  Hanford, 
and  when  they  occur  in  such  large 
.numbers  they  probably  do  considerable  injury 
to  the  vine  as  root  feeders. 

When  young  vines  are  planted  in  soil  which 
has  previously  been  in  hay  or  pasture  the  wire 
worms  may  attack  the  bark  just  below  the  sur- 
face and  kill  the  vine  by  girdling  it.  Rupestris 
St.  George  seems  particularly  susceptible  to  this 
form  of  attack.  The  vines  may  be  saved  if  the 
wire  worms  congregated  around  the  collar  of  the 
vine  one  or  two  inches  below  the  surface  are 
collected  by  hand  in  time. 

Treatment. — We  know  of  no  generally  satisfac- 
tory remedy  for  these  insects.  Turning  up  the 
soil  is  recommended  for  the  same  insect  in  the 


FIG.  22.    Young  vine  gir- 
dled by  wire  worms. 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


East,  especially  in  the  fall  or  winter,  but  such  an  operation  is  likely  to 
prove  of  little  value  in  our  climate  here.  Besides,  most  of  those  found 
around  the  vines  were  below  the  reach  of  any  plow.  Clean  culture  in 
the  vineyard  will  do  as  much  as  anything,  since  ordinarily  they  feed 
upon  the  roots  of  grasses  and  other  plants  at  a  comparatively  short 
distance  from  the  surface. 


ERINOSE.* 

Erinose  is  a  disease  of  the  vine  characterized  by  swellings  on  the 
upper  surface  of  the  leaves,  and  corresponding  depressions  on  the 

lower  surface.  These  swell- 
ings, when  numerous,  cause 
considerable  deformation  of 
the  leaves,  but  not  the  change 
of  color  to  yellow  or  brown 
which  is  characteristic  of 
most  fungous  diseases.  Even 
very  badly  affected  leaves 
retain  almost  their  normal 
green  color  on  the  upper  sur- 
face until  late  in  the  season. 
The  depressions  on  the 
under  side  are  coated  with  a 
thick  felt-like  covering, 
which,  at  first  pure  white, 
gradually  turns  rusty  and 
finally  becomes  dark  brown. 
Generally,  the  swellings  and 
corresponding  depressions 
are  isolated  and  few  in  num- 
ber on  the  affected  leaves,  but  in  severe  cases  they  are  numerous  enough 
to  become  confluent  and  the  whole  lower  surface  is  then  completely 
hidden  by  the  felt-like  covering.  Occasionally,  indeed,  the  felt-like 
material  extends  to  the  upper  surface  in  narrow  strips  bordering  the 
veins,  and  may  even  be  found  on  the  petioles  and  flower  clusters. 

Most  of  the  specimens  received  at  the  laboratory  are  sent  under  the 
impression  that  they  are  attacked  by  a  fungus,  and,  in  fact,  the  coating 
has  a  strong  superficial  resemblance  to  some  fungous  growths.  A  micro- 
scopic examination  shows,  however,  that  it  consists  of  a  mass  of  hyper- 
trophied  hairs  or  abnormal  outgrowths  of  the  epidermal  cells  of  the 
leaf.  T.hey  are  larger,  more  abundant,  and  more  persistent  than  the 

*  Revised  from  Bulletin  No.  136,  by  F.  T.  Bioletti  and  E.  H.  Twight. 


FIG.  23.  Vine  leaf  affected  with  Erinose — upper  surface. 


BULLETIN  192.  INSECTS   INJURIOUS   TO   THE   VINE.  135 

normal  leaf-hairs  of  the  leaf,  and  differ  also  in  being  often  branched 
and  usually  unicellular.  This  abnormal  growth,  in  common  with 
similar  growths  found  on  other  pl'ants,  is  called  an  erineum,  from  a 
Greek  word  meaning  woolly.  This  is  the  derivation  of  the  word  erinose, 
which  means  woolly  disease — a  very  appropriate  name.  The  erinea  of 
leaves  were  formerly  supposed  to  be  of  fungous  origin,  but  are  now 
known  to  be  due  to  the  attacks  of  minute  mites.  The  feeding  of  these 
mites  exert  a  stimulating  effect  upon  the  epidermal  cells  of  the  leaf, 
which  causes  them  to  grow  out  into  the  abnormal  hair-like  processes 
already  described.  The  mite  causing  erinose  of  the  vine  is  known  as 
Eriophyes  vitis,  and  is  related  to  the  mites  causing  a  similar  disease  of 
the  walnut  and  the  leaf  blister  of  the  pear,  both  of  which  are  very 
common  in  California. 

The  Eriophyes  vitis  is  not  a  true  insect,  but  a  mite  or  acarid  belong- 
ing to  the  class  of  Arachnida  to  which  belong  also  spiders,  scorpions, 
ticks,  and  our  common  red  spider  so  destructive  to  fruit  trees.  These 
mites  are  extremely  minute,  and  only  a  practiced  eye  can  perceive  them 
among  the  tangled  mass  of  erineum  on  the  leaf,  by  the  aid  of  an  ordinary 
hand  magnifier,  and  then  only  with  great  difficulty. 

Amount  of  Injury. — Erinose  was  formerly  considered  to  be  a  very 
serious  disease  of  the  vine,  owing  to  the  fact  that  its  effects  were  con- 
fused with  those  of  the  powdery  mildew.  It  is  only  in  very  exceptional 
cases  that  it  is,  alone,  capable  of  doing  serious  injury  to  the  vine  or  its 
crop.  When  accompanying  oidium  or  drought  it  may,  however,  per- 
ceptibly increase  the  damage  due  to  these  causes.  When  very  abundant 
it  may  seriously  interfere  with  the  growth  of  young  vines,  but  accord- 
ing to  Mayet,  never  damages  old  vines,  except  by  interfering  slightly 
with  the  ripening  of  the  canes,  or  at  most  causing  an  almost  impercep- 
tible diminution  of  crop.  All  varieties  of  vines  are  not  equally  attacked. 
According  to  Ravaz,  certain  American  species  such  as  Berlandieri, 
Mustang,  Cinerea,  Cordifolia,  and  Scuppernong  are  immune.  All  vari- 
eties of  Vinifera  are  susceptible,  but  not  equally.  Of  varieties  culti- 
vated in  California,  Sauvignon,  Sirah,  Marsanne,  and  Gamay  Teinturier 
are  said  by  Ravaz  to  be  little  subject  to  attack;  while  Aramon,  Cinsaut, 
and  Frontignan  (Small  Muscatel)  are  very  susceptible.  The  worst 
cases  so  far  observed  in  California  have  been  on  Flame  Tokay  and 
Mission,  but  it  has  been  found  also  on  other  varieties,  among  them 
Zinfandel  and  Muscat. 

Distribution  in  California. — The  first  specimens  of  erinose  received 
by  the  Experiment  Station  we-re  sent  from  Windsor,  Sonoma  County, 
in  1896.  The  next  year  affected  leaves  were  received  from  Healdsburg 
and  Dry  Creek,  in  the  same  county.  All  these  cases  were  upon  Mission 
vines.  Since  then  specimens  of  the  disease  have  been  received  from 
nearly  every  grape-growing  county  of  the  State. 


336  UNIVERSITY  OP   CALIFORNIA EXPERIMENT   STATION. 

Methods  of  Treatment. — Since  sulfuring  the  vines  for  the  treatment  of 
oidium  has  become  general  in  France,  there  has  been  little  trouble  with 
erinose.  The  mite  seems  as  sensitive  to  the  fumes  of  sulfur  as  the  red 
spider,  and  several  sulfurings  during  the  late  spring  and  early  summer 
are  recommended  for  the  control  of  the  mite.  The  only  vineyards  which 
have  been  found  badly  affected  in  California  are  those  in  which  little  or  no 
sulfuring  has  been  done,  or  those  where  the  growth  of  foliage  has  been 
so  luxuriant  as  to  prevent  the  evaporation  of  the  sulfur  by  the  sun. 
In  the  latter  cases  the  vines  are  so  strong  that  they  practically 
receive  no  harm  from  the  disease.  Tests  made  on  Tokay  vines  indicate 
that  the  erinose  can  be  easily  and  readily  controlled  at  any  stage  in 
California  by  sulfuring.  In  severe  cases  a  winter  treatment  of  the  vine 
stumps  is  practiced  in  France.  This  treatment  consists  in  pouring 
about  one  quart  of  boiling  water  over  the  stump.  For  very  large 
stumps  a  somewhat  greater  amount  of  water  is  used,  and  for  smaller, 
vines  a  proportionate  amount.  This  method  is  said  to  be  very  efficacious, 
and  with  the  portable  boiler  constructed  for  the  purpose  two  men  can 
treat  from  fifteen  hundred  to  two  thousand  vines  per  day.  Cuttings 
taken  from  affected  vines  for  the  purpose  of  rooting  or  grafting  may  be 
thoroughly  disinfected  by  placing  them  in  hot  water  (122°  F.)  for  ten 
minutes.  If  this  is  done  carefully  all  the  mites  and  their  eggs  will  be 
destroyed  without  injury  to  the  cuttings. 


NEMATODE  ROOT  GALL. 

(Heterodera  radicola  (Greef)  Mull.) 

Nematodes  are  not  insects,  nor  are  they  very  closely  related  to 
insects.  They  belong  to  the  class  of  animals  known  as  Vermes  or  true 
worms.  The  common  earthworm  is  the  best  known  example  of  the 
class,  although  it  occupies  a  position  in  the  group  higher  than  that  of 
the  nematodes.  There  are  a  good  many  species  of  nematodes — some 
living  in  the  ground,  a  good  many  are  parasites  on  animals,  and  a  few 
live  parasitically  on  plants.  Often  in  moist  soil,  rich  in  humus,  such  as 
vegetable  gardens,  there  may  be  large  numbers  of  very  minute  whitish 
transparent  worms.  These  are  nematodes,  however,  that  do  no  notice- 
able injury  to  plants,  and  it  is  only  the  parasitic  species,  of  which  the 
subject  of  this  account  is  an  example,  that  are  of  any  concern  to  growers 
of  crops. 

The  species  of  nematode  worm  that  attacks  the  grapevine  in  this 
State — according  to  Dr.  Ernst  Bessey  of  the  Department  of  Agricul- 
ture, who  is  at  present  engaged  in  an  investigation  of  this  group — is 
Heterodera  radicola  (Greef)  Mull.  This  species  is  widely  distributed 


BULLETIN  192. 


INSECTS   INJURIOUS   TO   THE  VINE. 


137 


over  the  world,  and  attacks  a  large  variety  of  plants.  In  the  Argentine 
Republic  it  is  said  to  be  the  most  destructive  disease  of  the  vine  occur- 
ring in  that  country.*  In  the  United  States,  outside  of  greenhouses, 
nematodes  are  chiefly  injurious  in  the  Southern  States  and  in  California. 

This  parasitic  species  is  an  exceedingly  small  wormlike  creature 
about  one  seventy-fifth  of  an  inch  long,  and  of  a  transparent  whitish 
color.  It  has  a  sharp  slender  organ  on  the  head  that  enables  it  to  make 
its  way  into  the  more  tender  portions  of  the  roots,  where  it  embeds  itself 
in  the  tissues.  Here  it  develops,  and  lays  the  eggs  from  which  succeed- 
ing generations  arise.  These  may  scatter  through  the  soil  and  attack 
other  portions  of  the  root.  By  means  of 
this  sharp  lancelike  organ  they  are  able  to 
draw  nourishment  from  the  roots.  It  is  not  M 
so  much  this  direct  drain  on  the  roots,  how- 
ever, that  causes  the  damage  as  it  is  in  the 
decay  of  the  hypertrophied  tissue  due  to  the 
irritation  caused  by  the  work  of  the  worms. 
They  make  conditions  favorable  for  the 
attack  of  wood-rot  fungi,  which  hasten  the 
decay.  The  roots  of  vines  infested  with 
this  worm  show  numerous  swellings,  some- 
what like  that  due  to  phylloxera.  The 
nodosities  or  swellings  caused  by  phyllox- 
era, however,  are  most  conspicuous  and  are 
larger  on  the  smaller  roots,  while  those  of 
nematodes  are  largest  on  the  larger  roots. 
The  swellings  are  also  of  firmer  consistency 
than  those  of  phylloxera. 

The  general  effect  on  the  vine  is  not  very  different  from  that  of  the 
phylloxera.  The  distribution  of  the  affected  vines  will,  however,  gener- 
ally distinguish  the  two.  Vineyards  infested  with  phylloxera  show  the 
characteristic  oil-spots,  the  interior  vines  being  worst  affected  and  grad- 
ually diminishing  in  injury  toward  the  periphery  of  the  affected  spot. 
The  amount  of  injury  is  said  to  vary  with  the  soil  conditions,  but  the 
authorities  apparently  are  not  agreed,  some  claiming  less  injury  in 
light,  sandy  soil  and  others  the  reverse.  Moisture  is,  no  doubt,  the 
most  important  factor  in  favoring  their  development.  In  California 
this  pest  seems  to  be  most  common  on  vines  in  the  Fresno  section,  and, 
in  general,  this  is  a  section  of  sandy  soil. 

Control. — No  satisfactory  remedy  has  yet  been  found  for  controlling 
parasitic  nematodes.  In  greenhouses  the  usual  procedure  is  to  sterilize 
the  soil,  but  this,  obviously,  is  not  applicable  to  a  vineyard.  However, 

*Boletin  del  Ministerio  de  Agricultura,  Buenos  Ayres,  Mayo  de  1906. 


FIG.  24.  N.  Swellings  on  the  roots 
of  vine  caused  by  the  Nematode 
root  gall.  M,  M.  Eggs  of  the 
Nematodes  found  in  these  galls. 


138  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT   STATION. 

if  the  soil  is  known  to  be  infested,  disinfection  is  sometimes  practiced 
before  planting  out  young  vines.  This  is  done  by  an  application  of 
carbon  bisulfid  to  the  soil.  Trap  plants  have  also  been  used,  these  being 
annuals  that  are  pulled  up  before  the  nematodes  escape.  In  time  it 
may  be  found  that  resistant  stock  is  the  solution  of  the  problem.  In 
the  bulletin  already  referred  to  it  is  stated  that  the  Isabella  is  slightly 
resistant,  while  Vitis  riparia  has  shown  no  nodules  after  the  first  year. 
This  fact  is  interesting  as  a  suggestion  that  both  phylloxera  and 
nematodes  may  be  controlled  by  the  same  resistant. 


BULLETIN  192.  INSECTS  INJURIOUS  TO  THE  VINE.  139 


KEY  FOR  DETERMINING  THE  INSECT  INJURIES  TO  THE  VINE 
DESCRIBED  IN  THIS  BULLETIN. 


Injury  to  the  Leaves. 

No  part  of  the  leaf  eaten  away,  but  having  pale  spots,  or  being 
entirely  pale  yellow,  or  dried  up,  those  about  the  crown  of  the  vine, 
particularly  the  lower  ones,  worst  affected.  Vine  hopper,  page  111. 

Leaves  with  irregular  holes  eaten  out.  Flea  beetles,  page  128;  Grass- 
hoppers, page  122;  or  Leaf  chafers,  page  132. 

Leaves  with  regular  chain-like  slits  eaten  away.    Root  beetles,  page  116. 

Leaves  rolled  up  from  one  side.     Leaf  rollers,  page  129. 

Leaves  entirely  devoured.  Army  worms,  page  124;  Grasshoppers, 
page  122;  Hawk  moth  larvss,  page  119. 

Leaves  with  swellings  on  upper  surface,  and  grayish  white  to  dark, 
brown  felt  covering  on  corresponding  depressions  on  under  side.  Erinose, 
page  134. 

Injury  to  Petioles  and  Pedicels. 

Narrow  strips  of  uniform  size  eaten  away.     Root  beetle,  page  1 16. 

Injury  to  the  Berry. 

Narrow  strips  about  one  fourth  of  an  inch  long  gouged  out.  Root 
beetle,  page  116. 

Clusters  cut  off  and  dropped  to  ground.     Army  worm,  page  124. 

Injury  to  the  Roots. 

Long  strips  of  the  bark  eaten  away.     Root  beetle,  page  116. 

The  smaller  rootlets  only  eaten  of!'.     Wire  worm,  page  133. 

Nodosities  or  swellings,  largest  on  smaller  roots,  often  at  extreme  tip, 
decay  of  hypertrophied  tissue.  Phylloxera,  page  99. 

Nodosities  or  swellings  largest  on  larger  roots,  two  or  three  times  the 
diameter  of  those  caused  by  phylloxera,  and  of  firmer  consistency, 
none  at  extreme  tip.  Nematodes,  page  136. 

Injury  to  the  Whole  Vine. 

These  are  the  same  as  under  root  injury,  since  injury  to  the  roots 
affects  the  vine  as  a  whole. 

Vines  whose  canes  are  checked  in  growth  or  completely  stunted,  and 
if  leaves  have  chain-like  strips  eaten  out.  Root  worm,  page  116. 


140  UNIVERSITY  OF  CALIFORNIA EXPERIMENT   STATION. 

Vines  in  circular  spots  in  vineyard  showing  stunted  growth,  those 
in  center  of  spot  worst  affected  and  gradually  diminishing  outward. 
Phylloxera,  page  99. 

Vines  with  symptoms  similar  to  phylloxera,  but  not  in  well-defined 
circular  spots,  nor  with  interior  ones  worst  affected.  Nematodes,  page  136. 


HOW  TO  SEND  SPECIMENS. 

Insect  specimens  should  be  inclosed  in  a  wooden,  tin  or  strong  paste- 
board box.  No  provision  need  be  made  for  air.  Accompany  specimens 
with  samples  of  their  work.  If  roots  or  leaves,  wrap  in  moist  news- 
paper and  inclose  in  tight  box  to  prevent  drying.  If  phylloxera  is 
suspected,  place  pieces  of  roots  in  a  firm  box  that  is  absolutely  tight; 
.,or  otherwise  thoroughly  seal,  to  prevent  any  possibility  of  escape  in  the 
mails. 


STATION  PUBLICATIONS. 


STATION  PUBLICATIONS  AVAILABLE  FOR  DISTRIBUTION. 


REPORTS. 

1896.  Report   of    the    Viticultural    Work   during   the   seasons    1887-93,    with   data 

regarding  the  Vintages  of  1894-95. 

1897.  Resistant   Vines,    their    Selection,   Adaptation,   and   Grafting.      Appendix   to 

Viticultural  Report  for  1896. 

1898.  Partial  Report  of  Work  of  Agricultural  Experiment  Station  for  the  years 

1895-96  and  1896-97. 
1900.     Report  of  the  Agricultural  Experiment  Station  for  the  year  1897-98. 

1902.  Report  of  the  Agricultural  Experiment  Station  for  1898-1901. 

1903.  Report  of  the  Agricultural  Experiment  Station  for  1901-1903. 

1904.  Twenty-second  Report  of  the  Agricultural  Experiment  Station  for  1903-1904. 

TECHNICAL  BULLETINS— ENTOMOLOGICAL  SERIES. 

Vol.  1,  No.  1 — Wing  Veins  of  Insects. 

No.  2 — Catalogue  of  the  Ephydridae. 

BULLETINS. 

Reprint.  Endurance  of  Drought  in  Soils  of  the  Arid  Region. 

No.  128.  Nature,  Value  and  Utilization  of  Alkali  Lands,  and  Tolerance  of  Alkali. 

(Revised  and  Reprint,  1905.) 

133.  Tolerance  of  Alkali  by  Various  Cultures. 

140.  Lands  of  the  Colorado  Delta  in  Salton  Basin,  and  Supplement. 

141.  Deciduous  Fruits  at  Paso  Robles. 

142.  Grasshoppers  in  California. 

147.  Culture  Work  of  the  Substations. 

148.  Resistant  Vines  and  their  Hybrids. 

149.  California  Sugar  Industry. 

150.  The  Value  of  Oak  Leaves  for  Forage. 

151.  Arsenical  Insecticides. 

152.  Fumigation  Dosage. 

153.  Spraying  with  Distillates. 

154.  Sulfur  Sprays  for  Red  Spider. 
156.  Fowl  Cholera. 

158.  California  Olive  Oil ;  its  Manufacture. 

159.  Contribution  to  the  Study  of  Fermentation. 

160.  The  Hop  Aphis. 

161.  Tuberculosis  in  Fowls.      (Reprint.) 

162.  Commercial  Fertilizers.     (Dec.  1,  1904.) 

163.  Pear  Scab. 

164.  Poultry  Feeding  and  Proprietary  Foods.     (Reprint.) 

165.  Asparagus  and  Asparagus  Rust  in  California. 

166.  Spraying  for  Scale  Insects. 

167.  Manufacture  of  Dry  Wines  in  Hot  Countries. 

168.  Observations  on  Some  Vine  Diseases  in  Sonoma  County. 

169.  Tolerance  of  the  Sugar  Beet  for  Alkali. 

170.  Studies  in  Grasshopper  Control. 

171.  Commercial  Fertilizers.     (June  30,  1905.) 

172.  Further  Experience  in  Asparagus  Rust  Control. 

173.  Commercial  Fertilizers.     (December,  1905.) 

174.  A  New  Wine-Cooling  Machine. 

175.  Tomato  Diseases  in  California. 

176.  Sugar  Beets  in  the  San  Joaquin  Valley. 

177.  A  New  Method  of  Making  Dry  Red  Wine. 

178.  Mosquito  Control. 

179.  Commercial  Fertilizers.     (June,  1906.) 

180.  Resistant  Vineyards. 

181.  The  Selection  of  Seed- Wheat. 

182.  Analysis  of  Paris  Green  and  Lead  Arsenate.     Proposed  Insecticide  Law. 

183.  The  California  Tussock-moth. 

184.  Report  of  the  Plant  Pathologist  to  July  1,  1906. 
385.  Report  of  Progress  in  Cereal  Investigations. 

186.  The  Oidium  of  the  Vine. 

187.  Commercial  Fertilizers.      (January,  1907.) 

188.  Lining  of  Ditches  and  Reservoirs  to  Prevent  Seepage  and 

189.  Commercial  Fertilizers.     (June,  1907.) 

190.  The  Brown  Rot  of  the  Lemon. 

191.  California  Peach  Blight. 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 


CIRCULARS. 

No.  1.  Texas  Fever.  No.  23. 

2.  Blackleg.  24. 

3.  Hog  Cholera.  25. 

4.  Anthrax. 

5.  Contagious  Abortion  in  Cows.  26. 
7.  Remedies  for  Insects. 

9.     Asparagus  Rust.  27. 

10.  Reading  Course  in  Economic 

Entomology.      ( Revision. ) 

11.  Fumigation  Practice.  28. 

12.  Silk  Culture. 

13.  The  Culture  of  the   Sugar  Beet. 

15.  Recent   Problems   in   Agriculture.  29. 

What  a  University  Farm  is  For. 

16.  Notes  on  Seed- Wheat. 

17.  Why      Agriculture      Should      Be 

Taught  in  the  Public   Schools. 

18.  Caterpillars  on  Oaks.  30. 

19.  Disinfection   of   Stables.  31. 

20.  Reading  Course  in  Irrigation. 

21.  The  Advancement  of  Agricultural 

Education.  32. 

22.  Defecation    of    Must    for    White  33. 

Wine. 


Pure  Yeast  in  Wineries. 

Olive  Pickling. 

Suggestions  Regarding  Exam- 
ination of  Lands. 

Selection  and  Preparation  of 
Vine  Cuttings. 

Marly  Subsoils  and  the  Chlo- 
rosis or  Yellowing  of  Citrus 
Trees. 

A  Preliminary  Progress  Report 
of  Cereal  Investigations.  1905- 
1907. 

Preliminary  Announcement  con- 
cerning Instruction  in  Practi- 
cal Agriculture  upon  the 
University  Farm,  Davisville, 
Cal. 

White  Fly  in  California. 

The  Agricultural  College  and  Its 
Relationship  to  the  Scheme  of 
National  Education. 

White  Fly  Eradication. 

Packing  Prunes  in  Cans.  Cane 
Sugar  vs.  "Beet  Sugar. 


Copies  may  le  had  on  application  to  DIRECTOR  OF  EXPERIMENT  STATION,  Berkeley,  Cal. 


OFTHE 

UNIVERSITY 

OF 

^.A  L  «  F^ n  *^_ 
UNIVERSlVV  (ff  {JALIFORNIA  PUBLICATIONS. 

COLLEGE  OF  AGRICULTURE, 

AGRICULTURAL  EXPERIMENT  STATION, 


THE  BEST  WINE  GRAPES  FOR  CALIfORNIA.— PRUNING  YOUNG 
VINES.— PRUNING  THE  SULTANINA. 


BY  F.  T.  BIOLETTI. 


An  ideal  vine  at  second  winter  pruning. 

BULLETIN    No.    193. 

(Berkeley,  Cal.,  November,  1907.) 


SACRAMENTO: 

w.  w.  SHANNON,     :     :     :     :     SUPERINTENDENT  STATE  PRINTING. 

1907. 


BENJAMIN  IDE  WHEELER,  Ph.D.,  LL.D.,  President  of  the  University. 


EXPERIMENT     STATION     STAFF. 

E.  J.  WICKSON,  M.A.,   Director  and  Horticulturist. 

E.  W.  HILGARD,   Ph.D.,  LL.D.,   Chemist. 

W.  A.   SETCHELL,   Ph.D.,   Botanist. 

ELWOOD  MEAD,  M.S.,  C.E.,  Irrigation  Engineer. 

C.  W.  WOODWORTH,  M.S.,  Entomologist. 

R.    H.    LOUGHRIDGE,    Ph.D.,    Agricultural    Geologist    and    Soil    Physicist.       (Soils, 

Alkali.) 

M.  E.  JAFFA,  M.S.,  Nutrition  Expert,  in  charge  of  the  Poultry  Station. 
G.  W.  SHAW,  M.A.,  Ph.D.,  Agricultural  Technologist,  in  charge  of  Cereal  Stations. 
GEORGE  E.  COLBY,  M.S.,  Chemist.      (Fruits,  Waters,  Insecticides.) 
RALPH  E.  SMITH,  B.S.,  Plant  Pathologist  and  Superintendent  of  Southern  California 

Pathological  Laboratory  and  Experiment  Station. 
A.  R.  WARD,  B.S.A.,  D.V.M.,  Veterinarian  and  Bacteriologist. 

E.  W.  MAJOR,  B.Agr.,  Animal  Industry  and  Manager  of  University  Farm. 

F.  T.  BIOLETTI,  M.S.,  Viticulturist.      (Grapes,  Wine  and  Zymology.) 
H.  M.  HALL,  M.S.,  Assistant  Botanist. 

H.  J.   QUAYLE,  A.B.,   Assistant  Entomologist. 

W.    T.    CLARKE,    B.S.,    Assistant    Horticulturist    and    Superintendent    of    University 

Extension  in  Agriculture. 

JOHN  S.  BURD,  B.S.,  Chemist,  in  charge  of  Fertilizer  Control. 
C.  M.  HARING,  D.V.M.,  Assistant  Veterinarian  and  Bacteriologist. 

J.    W.    MILLS,    Assistant   Horticulturist,     {     Citrus  Experiment  station,  Riverside. 

T.   F.   HUNT,   B.S.,      "  ) 

E.   B.   BABCOCK,  B.S.,  Assistant  Plant  Pathologist. 

E.  H.  SMITH,  M.S.,  Assistant  Plant  Pathologist. 

H.  J.  RAMSEY,  M.S.,  Assistant  Plant  Pathologist,  )     Southern  California  Pathologi- 

C.   O.    SMITH,   M.S.,  "  "  "  f        cal  Laboratory.     Whittier. 

R.  E.  MANSELL,  Assistant  in  Horticulture,  in  charge  of  Central  Station  Grounds. 

GEO.   W.  "LYONS,  B.S.,  Assistant  in  Soil  Laboratory. 

RALPH  BENTON,  B.S.,  Assistant  in  Entomology. 

A.  J.  GAUMNITZ,  M.S.,  Assistant  in  Cereal  Investigations. 

HANS  C.  HOLM,  B.S.,  Assistant  in  Zymology. 

P.  L.  McCREARY,  B.S.,  Laboratory  Assistant  in  Fertilizer  Control. 

C.  WESTERGAARD,    B.S.,  Assistant  in  Farm  Mechanics. 

M.  E.  STOVER,  B.S.,  Assistant  in  Agricultural  Chemical  Laboratory. 
RACHAEL  CORR,  M.A.,  Assistant  in  Cereal  Laboratory. 

D.  R.  HOAGLAND,  A.B.,  Assistant  in  Agricultural  Chemical  Laboratory. 
D.  L.  BUNNELL,  Clerk  to  the  Director. 


JOHN  TUOHY,  Patron,  j.          Tuiare  Substation,  Tulare. 

J.  T.  BEARSS,  Foreman,  } 

J.  W.  ROPER,  Patron,  )          University  Forestry  Station,  Chico. 

E.  C.  MILLER,  In  charge,        } 

ROY  JONES,  Patron,  )          University  Forestry  Station,  Santa  Monica. 

N.  D.  INGHAM,  Foreman,  \ 

VINCENT    J.     HUNTLEY,  Foreman     of    California     Poultry    Experiment     Station, 
Petaluma. 

The  Station  publications  (REPORTS  AND  BULLETINS),  so  long  as  avail- 
able, will  be  sent  to  any  citizen  of  the  State  on  application. 


THE  BEST  WINE  GRAPES  FOR  CALIFORNIA, 

BY  F.  T.  BIOLETTI. 


The  question  is  often  asked:  "What  are  the  best  wine  grapes  for 
California?"  It  is  a  very  difficult  question  to  answer.  If  we  modify 
it  and  ask,  "What  wine  grape  is  it  most  advisable  to  plant?"  the  diffi- 
culty is  lessened  but  not  removed.  The  answer  will  depend  greatly  on 
the  point  of  view.  For  the  grape-grower  it  is  one  thing,  for  the  wine- 
maker  another,  for  the  consumer  still  another,  and  for  the  good  of  the 
industry  at  large  a  compromise  of  all  three. 

For  the  grape-grower  who  sells  his  grapes  for  so  much  a  ton  what- 
ever the  quality,  the  question  resolves  itself  into,  "  Which  is  the  heaviest 
bearer?" 

For  the  consumer  the  question  means  either  "What  grape  will  pro- 
duce good  wine  at  the  minimum  cost?"  or  "What  grape  will  produce 
the  best  wine  irrespective  of  cost?"  according  to  the  kind  of  consumer 
he  happens  to  be.  As  quantity  and  quality  are  to  a  great  extent 
inversely  proportionate,  these  views  are  widely  divergent. 

For  the  wine-maker  the  question  is  a  little  more  complicated,  but 
may  be  stated  essentially  as,  "What  grape  can  J  handle  with  the  most 
profit?"  This  profit  will  depend  on  the  difference  between  the  price  he 
is  forced  to  pay  the  grower  for  grapes  and  that  which  he  can  persuade 
the  consumer  to  pay  him  for  wine.  For  one  class  of  consumers  he 
must  get  cheap  grapes,  for  the  other  he  can  afford  to  pay  almost  any 
price,  providing  they  are  of  the  right  quality. 

For  the  good  of  the  industry  at  large  it  is  desirable  that  varieties 
should  be  planted  which  will  produce  as  large  a  crop  as  is  compatible 
with  such  quality  as  will  maintain  and  extend  the  markets  for  our  wine. 
These  markets  are  varied  in  character.  For  some,  cheapness  is  the 
essential  factor;  for  others,  quality.  Cheap  wines  can  be  produced  with 
profit  only  from  heavy-bearing  varieties  grown  in  rich  soil;  wines  of  the 
highest  quality  only  from  fine  varieties  grown  on  hillsides  or  other 
locations  where  the  crops  are  necessarily  less.  It  is  therefore  unwise  to 
plant  poor-bearing  varieties  in  the  rich  valleys  where  no  variety  can 
produce  a  fine  wine.  It  is  equally  unwise  to  plant  common  varieties  on 
the  hill  slopes  of  the  Coast  Ranges  where  no  variety  will  produce  heavy 
crops.  The  vineyards  of  the  San  Joaquin,  Sacramento,  and  other 
valleys  can  not  compete  with  the  vineyards  of  the  Coast  Ranges  in 
quality,  and  the  latter  can  not  compete  with  the  former  in  cheapness. 

Each  region  has  its  own  special  advantages  which,  if  properly  used, 
will  make  grape-growing  profitable  in  all,  and  instead  of  competing  each 


142  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

will  be  a  help  to  the  other.  The  danger  to  be  feared  by  the  grape- 
growers  of  the  Coast  Ranges  from  the  production  of  dry  wine  in  the 
interior  is  not  competition,  but  lies  in  the  bad  reputation  given  to 
California  wines  by  the  production  of  spoiled  and  inferior  wines.  If 
the  cheap  wines  of  the  valleys  are  uniformly  good  and  sound  the  market 
for  the  high-priced  fine  wines  of  the  hills  will  increase,  and  large 
quantities  of  the  Coast  Range  wines  will  be  used  for  blending  with  the 
valley  wines  to  give  them  the  acidity,  flavor,  and  freshness  which  they 
lack. 

In  order  to  obtain  these  results  it  is  necessary  that  varieties  suited  to 
each  region  and  to  the  kind  of  wine  should  be  planted.  No  variety 
which  is  not  capable  of  yielding  from  5  to  8  tons  per  acre  in  the  rich 
valley  soils  or  from  1-|  to  3  tons  on  the  hill  slopes  should  be  considered. 
On  the  other  hand,  no  variety  which  will  not  give  a  clean-tasting, 
agreeable  wine  in  the  valley  or  a  wine  of  high  quality  on  the  hills 
should  be  planted,  however  heavily  it  may  bear.  To  plant  heavy- 
bearing  inferior  varieties  such  as  Burger,  Feher  Szagos,  Charbono,  or 
Mataro  on  the  hills  of  Napa  or  Santa  Cruz  is  to  throw  away  the  chief 
advantage  of  the  location.  The  same  is  true  of  planting  poor-bearing 
varieties  such  as  Verdelho,  Chardonay,  Pinot,  or  Cabernet  Sauvignon 
in  the  plains  of  the  San  Joaquin. 

With  these  considerations  in  view,  the  following  suggestions  are  made 
for  planting  in  the  chief  regions  of  California: 

1.  Vineyard  for  Sweet    Wine  in  the  Interior   Valleys. — 

RED.                                          Proportion.  WHITE.                                         Proportion. 

Grenache \  Palomino.. _ & 

Alicante  Bouschet £  Beba ._. \ 

Tinta  Madeira i  Boal J 

The  Grenache  and  Alicante  Bouschet  are  heavy  bearers  with  short 
pruning.  The  former  naturally  takes  a  port  flavor  and  the  latter 
insures  sufficient  color.  The  Tinta  Madeira,  when  pruned  properly, 
bears  well  and  will  increase  the  quality  of  the  port  wine. 

The  Palomino  is  one  of  the  heaviest  and  most  regular  bearers  grown 
in  California  and  is  peculiarly  suited  for  sherry  making.  It  is  the 
principal  grape  of  the  Spanish  sherry  district.  The  Beba  bears  nearly 
or  quite  as  well  as  the  Palomino  and  is  of  rather  better  quality.  Both 
bear  with  short  pruning.  The  Boal  bears  good  crops  and  gives  a  sweet 
wine  of  high  quality. 

2.  Vineyard  for  Dry   Wine  in  the  Interior   Valleys.— 

RED.                                          Proportion.  WHITE.                                       Proportion. 

Valdepenas.. £  Burger & 

Lagrain J  West's  White  Prolific | 

St.  Macaire |  Vernaccia  Sarda £ 

The  Valdepenas  has  been  growing  for  nearly  twenty  years  at  the 
Tulare  Experiment  Station,  and  has  always  given  regular  and  good  crops 


BULLETIN  193.          THE  BEST  WINE  GRAPES  FOR  CALIFORNIA.  143 

with  short  pruning.  The  dry  red  wine  made  from  it  has  been  in  every 
way  satisfactory  and  much  superior  to  that  made  from  Bouschet,  Zin- 
fandel,  or  any  of  the  varieties  usually  grown  in  the  valley,  and 
approaches  more  nearly  than  any  other  variety  the  wines  of  the  cooler 
localities.  This  variety  has  been  planted  to  some  extent  in  the  cooler 
localities,  where  it  is  completely  out  of  place.  In  Napa  its  bearing  is 
unsatisfactory  and  its  wine  harsh.  The  vine  needs  a  hot  climate  to 
bring  out  its  best  qualities.  The  Lagrain  and  St.  Macaire  are  valuable 
on  account  of  their  intense  color,  which  at  Tulare  is  equal  to  that  of  the 
Bouschets  and  is  more  stable.  The  St.  Macaire  is  particularly  recom- 
mended on  account  of  its  high  acidity,  which  is  extremely  useful  for 
the  region.  The  Gros  Mansenc  retains  its  acid  even  better  than  the 
St.  Macaire,  and  is  also  deeply  colored,  but  it  has  not  borne  quite  so  well. 
The  Burger  has,  fortunately,  been  planted  extensively  in  the  hotter 
parts  of  the  interior,  and  probably  no  better  choice  could  be  made  for 
the  production  of  a  cheap,  light,  neutral  dry  white  wine  in  that  region. 
Its  acidity,  which  is  excessive  in  the  coast  counties,  is  normal  or  even 
low  in  the  interior.  For  this  reason,  and  in  order  to  give  a  little  more 
character,  it  should  be  blended  with  such  grapes  as  the  West's  White 
Prolific  and  the  Vernaccia  Sarda,  which  retain  their  acidity  at  Tulare 
better  than  any  other  white  grapes  tested. 

3.    Vineyard  for  Dry  Wine  in  the  Coast  Counties. — 

RED.                                         Proportion.  WHITE.                                      Proportion. 

Petite  Sirah £  Semillon £ 

Beclan. .._.. |  Colombar £ 

Cabernet  Sauvignon £  Sauvignon  blanc £ 

The  conditions  of  soil  and  climate  in  the  hills  and  valleys  of  the 
Coast  Ranges  are  so  varied  that  it  is  much  more  difficult  to  give  recom- 
mendations that  will  be  of  general  use  than  in  the  case  of  the  interior 
valleys.  In  some  parts  of  some  of  the  valleys  the  soil  is  so  rich  and 
productive  that  it  is  possible  to  grow  grapes  as  cheaply  as  in  the 
interior.  The  grapes  recommended  for  the  interior,  however,  would  not 
in  most  cases  be  suitable  on  the  Coast,  owing  to  the  difference  in  climate. 
As  a  rule,  the  grapes  which  are  suitable  to  the  hill  slopes  will  do  well  in 
the  valley,  making  up  in  quantity  what  they  lose  in  quality. 

Of  the  many  scores  of  red  varieties  which  have  been  widely  grown  in 
this  region,  the  Petite  Sirah  has  undoubtedly  given  the  most  generally 
satisfactory  results.  Some  growers  are  dissatisfied  with  its  bearing, 
but  most  report  that  it  produces  as  much  as  the  Zinfandel.  Ungrafted, 
it  requires  long  pruning.  Its  wine  is  of  excellent  quality,  but  apt  to 
be  somewhat  harsh.  This  harshness  can  be  avoided  by  careful  wine- 
making  and  by  blending  with  a  smooth  variety  such  as  the  Beclan. 
The  finest  red  wines  which  have  ever  been  made  in  California  are  the 
product  of  the  Cabernet  Sauvignon.  This  variety,  unfortunately,  has 


144  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

been  rejected  almost  everywhere  on  account  of  its  light  crops.  Very 
satisfactory  crops,  however,  can  be  obtained  if  care  is  taken  in  selecting 
cuttings  for  planting  and  a  suitable  system  of  pruning  adopted.  This 
variety,  like  most  others,  moreover,  bears  better  when  grafted  on  a  suit- 
able resistant  stock.  It  is  very  much  to  be  desired  that  a  certain  pro- 
portion of  this  variety  should  be  planted  in  all  the  coast  vineyards 
which  are  capable  of  producing  a  dry  red  wine  of  high  quality. 

No  white  grape  has  given  better  results  in  both  crop  and  quality 
than  the  Semillon.  The  Colombar  (sometimes  called  the  Sauvignon 
vert)  has  also  proved  itself  a  regular  bearer,  and,  Avhile  not  of  such 
high  quality  as  the  Semillon,  it  blends  very  well  with  that  variety  and 
serves  to  modify  its  aroma,  which  is  sometimes  excessive.  The  Sau- 
vignon blanc  increases  the  quality  of  the  wine,  but  like  the  Cabernet 
Sauvignon  requires  careful  cutting,  selection  and  pruning  to  give 
satisfactory  crops. 

4.    Vineyard 'for  Dry  Wine  in  the  cooler  parts  of  the  Coast  Counties. — 

RED.  Proportion.  WHITE.  Proportion. 

Beclan f  Frankeii  Riesling f 

Blue  Portuguese i  Johannisberg  Riesling.- $ 

In  certain  parts  of  the  coast  counties,  owing  to  the  frequent  occurrence 
of  ocean  fogs,  many  varieties  of  vines  do  not  ripen  their  fruit  properly. 
By  a  careful  selection  of  varieties,  however,  good  crops  of  well-ripened 
grapes  may  be  obtained.  It  is  in  these  localities  that  the  finest  light 
wines,  those  most  nearly  resembling  the  wines  of  the  Rhine,  can  be 
produced. 

The  Beclan  has  shown  itself  especially  suited  to  this  region,  and  has 
the  great  advantage  of  being  very  resistant  to  oidium.  The  Blue 
Portuguese  is  a  good  bearer,  ripens  easily,  and  blended  with  Beclan 
gives  a  good  wine  of  Burgundy  type.  The  best  Riesling  wines  are 
grown  near  the  coast  and,  undoubtedly,  profitable  vineyards  of  the 
Rhine  varieties  can  be  grown  in  this  region  if  proper  methods  of  grape- 
growing  and  wine-making  are  adopted. 

Undoubtedly  there  are  many  excellent  varieties  of  grapes  that  could 
be  grown  with  profit  which  are  not  mentioned  in  the  foregoing  lists. 
The  varieties  mentioned  are  simply  those  which  have  given  evidence  of 
being  most  generally  adapted  to  the  more  usual  conditions.  Under 
special  conditions  other  varieties  should  be  added  to  or  substituted  for 
those  named.  In  planting  a  new  vineyard  it  would  be  well  often  to 
choose  those  varieties  which  are  best  able,  by  blending,  to  correct  the 
defects  of  the  varieties  already  growing  in  the  district  If  the  bulk  of 
the  red  grapes  are  deficient  in  color,  it  would  be  well  to  plant  a  larger 
proportion  of  deeply  colored  varieties.  If  most  of  the  white  grapes  of 
the  region  are  of  poor,  quality,  lacking  in  character,  flavor,  or  acidity,  a 
larger  planting  of  the  finer  varieties  might  be  advisable.  It  is  good 


BULLETIN  193.          THE  BEST  WINE  GRAPES  FOR  CALIFORNIA.  145 

policy  to  plant  something  that  has  not  already  been  planted  in  too 
large  quantities,  providing  it  is  something  suitable  and  for  which  there 
will  be  a  demand.  Moreover,  a  larger  number  of  kinds  ripening  at 
different  times  would  be  a  great  convenience  in  a  large  vineyard,  by 
allowing  the  gathering  of  the  grapes  to  extend  over  a  longer  period. 

Finally,  a  few  suggestions  as  to  what  "  not  to  do." 

Don't  plant  Mataro,  Feher  Szagos,  Charbono,  Lenoir,  or  any  variety 
which  makes  a  poor  wine  everywhere. 

Don't  plant  Burger,  Green  Hungarian,  Mourastel,  Grenache,  or  any 
common  heavy-bearing  varieties  on  the  hill  slopes  of  the  Coast  Ranges. 
Vineyards  in  such  situations  must  produce  fine  wines,  or  they  will  not 
be  profitable. 

Don't  plant  Chardonay,  Pinot,  Cabernet  Sauvignon,  Malbec,  or  any 
light-bearing  varieties  in  rich  valley  soils.  No  variety  will  make  fine, 
high-priced  wine  in  such  situations,  and  heavy  bearers  are  essential  to 
the  production  of  cheap  wine. 

Don't  plant  Zinfandel,  Alicante  Bouschet,  or  any  of  the  varieties 
which  have  already  been  planted  in  large  quantities,  unless  one  is  sure 
that  the  conditions  of  his  soil  and  locality  are  peculiarly  favorable  to 
these  varieties  and  will  allow  him  to  compete  successfully. 

WINE   GRAPES   RECOMMENDED   FOR  CALIFORNIA. 

FOR  COAST  COUNTIES. 
Red  Wine  Grapes.  White  Wine  Grapes. 

1.  Petite  Sirah.  1.  Semillon. 

2.  Cabernet  Sauvignon.  2.  Colombar  (Sauvignon  vert). 

3.  Beclan.  3.  Sauvignon  blanc. 

4.  Tannat.  4.  Franken  Riesling. 

5.  Serine.  5.  Johannisberger. 

6.  Mondeuse.  6.  Traminer. 

7.  Blue  Portuguese.  7.  Peverella. 

8.  Verdot. 

FOR  INTERIOR  VALLEYS. 

Red  Wine  Grapes.  White   Wine  Grapes. 

1.  Valdepenas.  1.  Burger. 

2.  St.  Macaire.  2.  West's  White  Prolific. 

3.  Lagrain.  3.  Vernaccia  Sarda. 

4.  Gros  Mansenc.  4.  Marsanne. 

5.  Barbera.  5.  Folle  blanche. 

6.  Refosco. 

7.  Pagadebito. 

FOR  SWEET  WINES. 

Red  Grapes.       i  White  Grapes. 

1.  Grenache.  1.  Palomino. 

2.  Alicante  Bouschet/  2.  Beba. 

3.  Tinta  Madeira.  J  3.  Boal. 

4.  California  Black  Malvoisie.  4.  Perruno. 

5.  Monica.  *  5.  Mantuo. 

6.  Mission.  '  6.  Mourisco  branco. 

7.  Mourastel.  7.  Pedro  Ximenez. 

8.  Tinta  Amarella.x 


146 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


PRUNING  AND  TRAINING  OF  YOUNG  VINES. 

The  first  two  or  three  years  of  the  life  of  a  vineyard  are  perhaps  the 
most  important  from  the  point  of  view  of  the  profit  and  satisfaction  to 
be  obtained  from  it  later.  Vines  which  are  neglected  or  improperly 
treated  in  youth  can  never  be  given  that  shape 
which  is  indispensable  for  the  maximum  returns 
and  the  minimum  labor. 

Thousands  of  acres  of  new  vineyard  have  been 
planted  during  the  last  two  years,  and,  without 
attempting  to  write  a  complete  treatise  on  vine 
pruning,  a  few   practical  suggestions  regarding 
the  treatment  of  young  vines  should  be  useful. 
/Whatever  the  variety  of  vine  and  whatever  the\ 
j  system  of  pruning  to  be  ultimately  adopted,  the  f 
I  treatment  for  the  first  two  and  even  three  years  \ 
Us  practically  identical. 

FIRST   YEAR. 

Making  Cuttings. — The  considerations  which 
should  govern  us  in  the  choice  and  making  of 
cuttings  have  been  given  in  Circular  No.  26,  of 
this  Station,  "  Selection  and  Preparation  of  Vine- 
Cuttings."  The  mechanical  part  only  is  reviewed 
here. 

The  cuttings  should  be  made  from  wrell-ripened 
canes  of  medium  thickness  and  of  greater  or  less 
length,  according  to  the  climate  and  soil  of  the 
vineyard  in  which  they  are  to  be  planted.  The 
range  will  be  from  10  to  18  inches. 

Cuttings  are  most  conveniently  made  by  means 
of  ordinary  one-hand  pruning  shears.  In  mak- 
ing them,  the  lower  cut  should  be  made  just 
below  a  bud,  and  the  upper  just  above  a  bud. 
These  cuts  should  be  made  as  near  the  bud  as  is 
possible  without  danger  of  destroying  or  remov- 
ing the  diaphragm  (see  Fig.  2). 

It  is  best  to  remove  the  upper  bud,  either 
when  making  the  cuttings  or  afterwards,  though  this  is  not  absolutely 
necessary.  The  bud  from  which  growth  is  expected  is  the  second  from 
the  top.  The  reason  for  leaving  the  internode  above  is  to  protect  the 
second  bud  and  to  insure  its  strong  growth.  It  is  for  this  reason  that 
the  diaphragm  should  be  left.  If  removed,  the  pith  in  the  upper 


FIG.  1.     Properly  made 
cuttings. 


BULLETIN  193. 


PRUNING  AND  TRAINING  OF  YOUNG  VINES. 


147 


internode  will  be  exposed  to  alternate  wetting  and  drying,  and  may 
decay,  thus  weakening  or  killing  the  bud  below. 

In  planting,  the  cutting  should  be  placed  with  just  one  bud  above  the 
surface  of  the  ground,  as  indicated  by  the  dotted  line  in  Fig.  1.  It  is  a 
great  mistake  to  leave  more  than  one  bud  out  of  the  ground,  as  this 
increases  the  danger  of  drying  out. 

Pruning  Rooted  Vines.—  A  young  rooted  vine  before  planting  should 
have  all  its  roots  shortened  to  from  4  to  6  inches,  according  to  their 
vigor  (see  Fig.  3,  A,  B,  C).  If  the  soil  has  been  very  deeply  plowed 
and  it  is  desired  to  plant  the  vines  with  a  dibble,  there  is  no  objection 
to  cutting  back  the  roots  to  stubs  i  of  an  inch  long  (see  Fig.  3,  D). 
Such  a  vine  will  make  better  growth  in  deeply  prepared  soil  than  one 
with  longer  roots  planted  with  a  spade  in  shallow-plowed  soil. 

The  top  of  the  vine  should  be  thinned  to  one  cane,  the  strongest  and 
most  upright  being  left.  This  cane  must  be  shortened  to  two  good  buds, 


N.  Node. 


FIG.  2.    Structure  of  Vine  Cane. 
d.  Diaphragm.  I.    Internode. 


P.  Pith. 


making  the  cut  close  to  an  internode,  as  in  making  cuttings  (see  Fig. 
3,  C,  D). 

The  pruning  of  rooted  bench  grafts  is  practically  the  same  as  that  of 
ordinary  rooted  vines,  though  the  cutting  back  of  the  single  cane  to  two 
buds  is  best  deferred  until  after  planting  and  just  as  the  buds  com- 
mence to  swell  (see  Fig.  3,  B).  This  affords  some  protection  to  the 
graft,  and  makes  it  less  likely  to  dry*  out  before  the  sap  starts  and  the 
young  rootlets  are  formed.  All  scion  roots  (CR)  above  the  union  (U) 
and  all  suckers  (SS)  from  below  the  union  should  be  carefully  removed 
(Fig.  3,  A). 

During  the  summer  of  the  year  the  vines  are  planted,  no  pruning  or 
training  of  any  kind  is  needed  in  most  cases.  For  this  reason  it  is 
nearly  always  unnecessary  to  stake  the  vines  when  they  are  planted. 
The  only  exception  to  this  is  when  strong-rooted  vines  are  planted  in  a 
rich,  moist  soil  in  which  they  will  make  a  very  large  growth  the  first 
year.  In  this  case  it  is  desirable,  though  not  quite  necessary,  to  stake 


148 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 


the  vines  immediately  after  planting 
and  to  adopt  the  method  of  summer 
treatment  described  below  for  the 
second  year. 

In  most  cases  it  is  best  to  allow  all 
the  shoots  to  remain  to  feed  the  vine 
and  to  insure  a  good  root  growth  the 
first  year. 

Staking. — In  the  autumn  or  winter  fol- 
lowing planting,  the  vines  should  be 
staked,  either  before  or  after  pruning, 
but  in  any  case  some  time  before  the 
buds  start  in  the  spring. 


B 


It 


FIG.  3.    Methods  of  pruning  rooted  vines. 

A.  Rooted  vine  (bench  graft)  before  pruning—  r, 

union.    &S,  stock  suckers.     CR,  scion  root. 

B.  Rooted  bench-graft  pruned  for  planting. 

C.  Rooted  cutting  pruned  for  planting. 

D.  Rooted  cutting  pruned  for  planting  with  dibble. 


BULLETIN  193.  PRUNING  AND  TRAINING  OF  YOUNG  VINES.  149 

The  kind  of  stake  used  will  depend  on  the  variety  of  vine  and  on  the 
method  of  pruning  to  be  ultimately  adopted.  For  ordinary  short- 
pruning,  the  stake  should  be  of  such  length  that,  after  being  driven  into 
the  ground,  sufficient  will  be  below  the  surface  to  keep  it  firm  and  prevent 
its  being  loosened  by  the  force  of  the  wind  acting  on  the  vine  which  is 
tied  to  it,  and  sufficient  above  the  surface  to  extend  1  or  2  inches  above 
the  height  at  wrhich  it  is  intended  to  head  the  vines.  It  should  be  from 
l^r  to  1^  inches  square,  according  to  its  length. 

In  firm  ground,  for  small-growing  vines  such  as  Zinfandel,  a  stake 
li  by  1^  inches  and  27  inches  long  will  be  sufficient.  This  will  allow 
15  inches  to  be  driven  into  -the  ground  and  leave  12  inches  above, 
which  is  enough  for  vines  to  be  headed  at  10  inches.  If  the  ground  is 
loose  or  sandy  a  30-inch  stake  driven  18  inches  into  the  ground  will  be 
'  needed.  For  strong-growing  varieties,  such  as  Carignane  or  Tokay? 
especially  when  planted  in  rich  soil,  a  stake  1^  by  1^  inches  and  36 
inches  long  will  be  necessary,  and  15  or  18  inches  of  this  should  be  left 
above  the  ground.  This  will  permit  the  heading  of  the  vines  at  15 
inches. 

If  the  vines  are  to  be  trellised  with  one  wire,  a  36-inch  stake  driven 
18  inches  into  the  ground  is  the  proper  length.  If  two  wires  are  to  be 
used,  a  48-inch  stake  will  be  needed,  leaving  30  inches  above  the 
surface. 

If  the  vines  are  to  be  pruned  long  and  the  canes  tied  to  the  stake,  a 
5-foot  stake  will  usualty  be  needed,  and  this  must  be  stronger,  2  by  2 
inches  square.  This  stake  should  be  driven  2  feet  into  the  ground. 

These  dimensions  are  all  smaller  than  are  usual  in  California,  but 
are  quite  sufficient  for  all  practical  purposes.  The  stake  should  be 
placed  1  to  2  inches  from  the  vine  on  the  side  opposite  to  the  prevailing 
heavy  winds.  The  force  of  the  wind  will  thus  keep  the  vine  pressed 
against  the  stake  and  the  tying  material  is  less  liable  to  break. 

First  Winter  Pruning. — In  California,  the  young  vines  may  be  pruned 
at  any  time  after  the  leaves  have  fallen,  except  in  sections  very  subject 
to  spring  frosts,  where  it  is  sometimes  advisable  to  defer  the  pruning 
until  after  the  top  buds  of  the  canes  start. 

The  way  the  vines  are  to  be  pruned  will  depend  altogether  on  the 
growth  they  have  made.  If  the  growth  has  been  small  the  tops  are 
pruned  exactly  like  rooted  vines  before  planting.  All  the  canes  are 
removed  entirely,  except  the  strongest,  and  this  is  cut  back  to  two  buds, 
as  in  Fig.  3,  C,  D  (see  Fig.  4,  a). 

Any  vines  which  have  made  a  strong  growth  and  possess  at  least  one 
cane  of  which  a  sufficient  length  is  well  ripened  may  be  pruned  for 
tying  up.  All  the  canes  are  removed  entirely,  except  the  strongest,  and 
this  is  cut  back  to  10, 15,  or  18  inches,  according  to  the  height  at  which 
it  is  intended  to  head  the  vine  (see  Fig.  5,  a).  The  top  cut  is  made 


150 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


through  a  bud,  just  as  in  making  cuttings.  This  will  facilitate  tying 
up  and  insure  the  healthy  growth  of  the  top  bud. 

Sometimes,  even  when  the  vine  has  made  sufficient  growth,  the  canes 
are  prostrate  or  crooked  and  none  can  be  tied  up  straight  to  the  stake. 
In  this  case  the  vine  must  be  pruned  like  a  weak  vine — that  is,  thinned 
to  one  cane  and  this  cane  cut  back  to  two  buds. 

In  no  case  should  two  canes  of  any  length  be  left,  and  in  all  cases 
where  it  is  impossible  to  obtain  the  full  length  of  well-ripened  wood  for 
tying  up,  the  cane  should  be  cut  back  to  two  buds.  It  is  very  bad 
practice  to  leave  some  of  the  canes  of  intermediate  length,  as  this  causes 


FIG.  4. 


b  c 

Treatment  of  an  average  vine  during  second  season. 


a.  Winter  pruning. 

b.  Spring  pruning— removal  of  suckers  (S)  and  thinning  of  shoots  (W). 

c.  Summer  treatment— tying  to  stake  and  topping. 

the  vines  to  head  out  at  various  heights  and  produces  an  irregularity 
of  shape  which  can  never  be  remedied  and  which  interferes  with  regular 
pruning,  cultivation,  and  other  vineyard  work. 

The  idea  to  be  kept  in  mind  is  to  cut  back  each  winter  nearly  to  the 
ground — that  is,  to  two  buds  until  a  cane  is  produced  with  a  length  of 
well-ripened  wood  and  good  buds  equal  to  the  height  at  which  the  vine 
is  to  be  headed.  It  is  very  important  that  this  cane  should  be  straight, 
healthy,  and  well-ripened,  as  it  is  from  it  that  the  trunk  of  the  mature 
vine  develops.  All  the  vines  on  which  a  cane  has  been  left  should  be 
carefully  tied  up.  Two  ties  will  be  needed  in  most  cases.  A  half  hitch 
should  be  made  around  the  cane  below  the  swelling  left  by  the  bud 
which  has  been  removed,  and  the  cane  tied  firmly  to  the  top  of  the  stake. 


BULLETIN  193.         PRUNING  AND  TRAINING  OF  YOUNG  VINES.  151 

Another  tie  is  made  about  half-way  down  the  stake.  The  lower  tie 
need  not  be  very  tight,  and  in  any  case  the  tying  material  should  not 
be  passed  completely  around  the  cane,  except  above  the  top  bud,  or 
the  vine  will  be  strangled  when  it  commences  to  grow  (see  Fig.  5,  a). 
Any  kind  of  string  or  twine,  sufficiently  strong  to  withstand  the 
pressure  of  the  growing  vine  in  a  heavy  wind,  may  be  used.  Binding 
twine,  or  a  single  strand  of  good  baling  rope,  is  suitable.  No.  16  or  17 
galvanized  wire  is  preferred  by  some  and  is  better  than  string,  if  care 
is  taken  to  remove  the  bottom  ties  the  following  year  before  they 
strangle  the  vine.  Wire  is  a  little  more  expensive  and  takes  a  little 
longer  to  put  on  than  string,  but  holds  the  vines  better  and  can  be  used 
for  several  years. 

SECOND    YEAR. 

Summer  Pruning. — The  treatment  during  the  second  and  third 
spring  and  summer  is  of  great  importance  to  the  future  welfare  of  the 
vine.  A  little  judicious  care  at  this  period  will  avert  many  troubles 
in  later  years.  It  will  be  necessary  to  go  over  the  vineyard  four  or 
five  times  to  do  the  suckering,  topping,  and  tying  which  are  necessary. 

The  shoots  starting  from  the  vines  which  have  been  cut  back  to  two 
buds  should  be  thinned  to  a  single  one.  This  thinning  should  be  done 
as  soon  as  possible  in  such  a  way  that  it  is  never  necessary  to  remove  a 
shoot  more  than  3  or  4  inches  long  (see  Fig.  4,  b).  If  the  thinning 
is  deferred  until  the  shoots  are  a  foot  or  more  long  the  vine  will  be 
weakened  by  the  removal  of  so  much  foliage.  If  the  thinning  cannot 
be  done  early,  it  is  better  not  to  do  it  at  all.  The  object  of  this  thinning 
is  to  throw  all  the  force  and  growth  of  the  vine  into  the  cane  which 
is  to  form,  finally,  the  trunk  of  the  vine.  If  it  is  done  too  late  not 
only  does  the  growth  not  go  into  this  cane,  but  the  vine  is  weakened 
so  much  that  this  cane  does  not  grow  so  well  as  it  would  have  done 
without  thinning. 

The  first  thinning  can  be  done  with  the  first  hoeing,  and  the  second 
with  the  suckering.  The  suckering  consists  of  the  removal  of  all  shoots 
which  come  from  below  the  ground.  These  also  should  be  removed  as 
early  as  practicable,  both  to  avoid  weakening  the  vine  by  the  removal 
of  mature  leaves  and  also  because  a  young  sucker  is  much  more  easily 
separated  from  the  vine  at  this  time.  Every  sucker  must  be  cut  or 
broken  off  at  the  point  where  it  originates.  If  a  little  piece  of  the  sucker 
is  left,  several  new  suckers  will  start  at  the  same  place.  The  more 
completely  the  suckering  is  done  during  the  first  two  years,  the  less 
trouble  in  this  respect  there  will  be  in  later  years.  This  is  particularly 
true  of  grafted  vines. 

A  few  weeks  after  the  first  thinning,  the  single  shoot  which  has  been 
left  will  have  grown  10  or  15  inches.  At  this  length  it  should  be  tied 
up  to  the  stake  (see  Fig.  4,  c).  If  this  tying  is  neglected  or  deferred 


152 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


too  long,  a  heavy  wind  is  very  liable  to  break  off  the  whole  shoot.  A 
piece  of  string  tied  rather  loosely  about  the  middle  of  the  shoot  is  all 
that  is  needed.  If  the  vines  are  to  be  headed  high  (18  inches)  another 
tie  near  the  top  of  the  stake  may  be  necessary  later. 

For  vines  which  are  making  only  a  moderate  growth  this  is  all  the 
treatment  needed  during  the  summer.  Strong-growing  vines  in  rich 
soil,  however,  should  be  topped. 

Topping. — The  object  of  this  topping  is  to  force  the  shoot  to  send  out 
laterals  at  the  right  height  above  the  surface  of  the  soil,  to  be  used  as 


FIG.  5.    Treatment  oi  average  vine  during  the  third  season,  or  of  a  vigorous  vine  during  the  second. 

a.  Vine  pruned  to  one  cane  and  tied  to  stake. 

b.  Removal  of  suckers  (S)  and  lower  shoots  (W)  in  spring. 

c.  Vine  in  summer  at  time  of  pinching. 

spurs  during  the  following  year.  This  topping  is  an  operation  which 
requires  a  good  deal  of  judgment.  If  the  topping  is  done  too  soon, 
laterals  will  not  start,  but  a  new  terminal  shoot  will  be  formed.  This 
is  not  a  serious  defect,  however,  but  simply  necessitates  a  second  top- 
ping two  or  three  weeks  later.  Neither  will  the  laterals  start  if  the 
topping  is  done  too  late,  or  if  they  start  they  will  not  mature,  and  the 
vine  is  weakened  by  the  removal  of  foliage  without  any  compensating 
advantage. 

Until  experience  has  shown  the  proper  time  for  the  variety  and 
locality,  it  is  best  to  top  when  the  shoot  has  grown  to  from  8  to  12 
inches  above  the  top  of  the  stake,  and  if  necessary  top  again  later. 


BULLETIN  193.        PRUNING  AND  TRAINING  OF  YOUNG  VINES.  153 

The  shoot  should  be  topped  within  1  or  2  inches  of  the  top  of  the 
stake,  if  the  stakes  have  been  chosen  and  driven  as  advised  above 
(see  Fig.  4,  c).  This  will  insure  the  growth  of  laterals  just  where  they 
are  needed  for  the  next  winter  pruning. 

The  vines  on  which  a  cane  has  been  left  and  tied  up  during  the  pre- 
ceding winter  must  be  treated  a  little  differently.  The  removal  of 
underground  shoots  or  suckers  is  the  same.  Instead  of  thinning  out 
the  shoots  to  a  single  one,  as  for  the  vines  just  described,  all  the  shoots 
should  be  left  to  grow,  except  those  too  near  the  ground  (see. Fig.  5,  b). 

As  a  rule,  all  shoots  between  the  ground  and  the  middle  of  the  stakes 
should  be  taken  off.  It  is  even  more  important  that  this  should  be 
done  early  than  in  the  case  described  above.  If  the  lower  shoots  are 
allowed  to  become  large  and  then  removed,  not  only  is  the  vine  weak- 
ened by  the  removal  of  mature  leaves,  but  the  stem  of  the  vine  is 
suddenly  exposed  to  the  direct  rays  of  the  hot  sun  and  is  very  liable  to 
injury.  This  injury  does  not  show  by  a  peeling  off  of  the  bark  as  with 
fruit  trees,  but  by  a  general  weakening  and  dwarfing  of  the  vine. 

The  shoots  coming'  from  the  upper  half  of  the  cane  are  to  form  the 
spurs  for  the  following  winter  pruning,  and  can  often  be  left  to  grow 
without  further  treatment. 

If  the  growth  is  very  rapid  and  succulent,  however,  it  is  necessary  to 
pinch  them,  or  the  first  heavy  wind  may  break  them  off  (see  Fig.  5,  c). 

Pinching  consists  of  the  removal  of  1  or  2  inches  of  growth  at  the 
extreme  tip  of  the  shoot.  This  delays  the  growth  in  length  temporarily 
and  gives  the  shoot  time  to  strengthen  its  tissues  before  its  length  gives 
too  much  leverage  to  the  wind.  This  pinching  usually  has  to  be 
repeated  at  least  once. 

Pinching  may  be  replaced  by  topping  a  few  weeks  later,  but  the  latter 
is  somewhat  weakening  to  the  vine. 

In  all  summer  pruning — that  is,  removal  of  green  shoots  and  leaves — 
of  young  vines,  two  things  should  be  kept  in  mind:  First,  that  all 
summer  pruning  is  weakening;  second,  that  the  object  of  summer  prun- 
ing of  young  vines  is  to  direct  the  growth  as  much  as  possible  into 
those  parts  which  are  to  become  permanent  portions  of  the  mature 
vine.  The  weakening  effect  is  almost  nil  if  the  shoots  or  tips  are 
removed  when  they  are  very  small,  but  may  be  very  serious  if  large 
shoots  are  removed  or  heavily  topped.  When  a  large  shoot  covered 
with  leaves  is  removed  it  'is  a  total  loss  to  the  vine.  .When  a  small 
shoot  is  removed  the  food  materials  which  would  have  gone  into  that 
shoot  are  diverted  to  the  shoots  that  remain,  and  the  vigor  and  size  of 
the  latter  are  increased. 


154 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 


THIRD    YEAR. 

Winter  Pruning. — After  the  leaves  have  fallen  at  the  end  of  the  third 
•summer  every  vine  should  have  a  well-formed,  straight  stem  with  two, 
three,  or  more  canes  growing  from  the  upper  part,  and  the  formation  of 
the  "head"  or  crown  should  commence.  Any  vines  which  have  not 
been  brought  to  this  condition  must  be  pruned  like  two-  or  one-year- 
old  vines,  as  the  case  may  be. 

If  the  work  up  to  this  point  has  been  well  done,  the  formation  of  the 
head  is  a  simple  matter.  It  consists  in  leaving  two,  three,  or  four  spurs, 


FIG.  6.    Three-year-old  vines  after  pruning. 

a.  Average  vine  with  two  spurs. 

b.  Vigorous  vines  with  three  spurs,  the  lowest  of  which  is  to  be 

removed  the  following  year. 

c.  Vigorous  vine  with  three  spurs. 

arranged  as  symmetrically  as  possible  near  the  top  of  the  vine.  The 
stronger  the  vine,  as  evidenced  by  the  number,  length,  and  thick- 
ness of  the  canes,  the  larger  the  number  of  spurs  and  buds  that  should 
be  left. 

A  spur  consists  of  the  basal  portion  of  a  cane,  and  normally  of  two 
full  internodes.  This  leaves  two  buds  besides  the  base  bud.  The 
number  of  buds  to  leave  on  a  spur  depends  on  the  strength  or  thickness 
of  the  cane  from  which  the  spur  is  made.  A  thin,  or  weak,  cane  should 
be  cut  back  to  one  bud  or  even  to  the  base  bud.  A  strong  cane,  on  the 
other  hand,  should  be  left  with  three  buds  besides  the  base  bud. 

The  pruning  of  each  vine  requires  judgment,  and  it  is  impossible  to 


BULLETIN  193.  PRUNING  THE  SULTANINA.  155 

give  an  inflexible  rule  to  follow.  The  ideal  of  a  perfect  vine  should  be 
kept  in  mind  and  each  vine  pruned  as  nearly  in  accordance  with  this 
ideal  as  circumstances  permit.  Fig.  6  and  the  illustration  on  the  cover 
represent  nearly  perfect  three-year-old  vines  consisting  of  two  or  three 
symmetrically  placed  spurs  of  two  buds  each  ne"ar  the  top  of  the  stem. 
Sometimes  it  is  necessary  to  leave  a  spur  lower  down  (see  Fig.  6,  b}. 
This  spur  will  be  removed  the  following  year  after  it  has  produced  two 
or  three  bunches  of  grapes.  Sometimes  a  vine  may  be  very  vigorous 
but  have  only4wo  canes  properly  placed  for  making  spurs.  In  this 
case  the  spurs  should  be  left  longer — three  buds  and  even  in  extreme 
cases  four  buds  long. 


PRUNING  THE  SULTANINA.* 

This  variety  has  shown  itself  extremely  irregular  in  bearing  in  many 
vineyards  of  California.  The  variations  in  the  crop  of  different  years 
in  the  same  vineyard,  of  adjacent  vineyards  in  the  same  district,  and 
of  different  vines  in  the  same  vineyard  are  very  much  greater  than  is 
usual  with  most  other  varieties.  The  cause  of  this  seems  to  be  due,  in 
great  part  at  least,  to  defective  pruning. 

If  we  inquire  into  the  history  of  any  Sultanina  vineyard  we  find  very 
commonly  the  following  sequence  of  events:  During  the  first  four,  live 
or  six  years  the  vines  were  pruned  short,  grew  with  extraordinary 
vigor,  but  produced  very  few  grapes.  The  following  year  the  owner, 
hearing  that  long  pruning  was  necessary,  left  two,  three,  four,  or  more 
canes  four  or  five  feet  long  and  tied  them  up  vertically  to  a  high  stake. 
This  usually  resulted  in  a  large  crop.  The  same  method,  as  nearly  as 
practicable,  was  followed  during  subsequent  years,  with  gradually 
diminishing  success,  until  about  the  third  year  of  long  pruning  the 
crops  had  become  unsatisfactory  again. 

The  reason  for  this  sequence  of  events  is  easy  to  comprehend  when 
we  understand  the  principles  of  long  pruning  and  the  special  charac- 
teristics of  the  Sultanina. 

This  variety  bears  well  only  on  long  canes,  so  that  so  long  as  short 
pruning  is  practiced  the  crops  are  unsatisfactory.  The  first  year  in 
which  long  canes  are  left  the  crop  is  good,  because  a  large  proportion 
of  the  canes  tied  up  consist  of  bearing  wood.  Provision  is  seldom  made, 
however,  for  the  growth  of  new  canes  from  the  stump  to  furnish  bearing 
wood  for  the  following  years.  The  result  is,  that  after  the  second  or 
third  year  all  the  bearing  wood  is  at  the  top  of  the  stake,  and  the  vine 
must  be  pruned  short  again  or  suckers  and  watersprouts  left  as  long 

*This  is  the  correct  name  of  the  "  Thompson's  Seedless." 


156 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


canes.     Whichever  of  these  two   alternatives  is  chosen  the  result  will 
be  unsatisfactory. 

A  common  condition  of  a  Sultanina  vine  after  the  first  year  of  long 


FIG.  7.    Sultanina  vine  showing  effect  of  tying  fruit  canes  in  a  vertical  position. 
(From  a  photograph.) 

S.  Suckers  and  watersprouts.    F.  Strong  fruit  wood.    /.  Weak  fruit  wood. 
C.  Fruit  canes  of  the  previous  year  which  have  just  borne  a  crop. 

pruning  is  shown  in  Fig.  7.  If  the  fruit  canes  (C,  C)  of  the  previous 
years  are  removed,  nothing  remains  but  the  unfruitful  suckers  and 
watersprouts  (S,  S).  If  the  old  fruit  canes  (C,  C)  are  left  there  is  an 


BULLETIN  193. 


PRUNING   THE   SULTANINA. 


157 


abundance  of  fruit  wood  (F,  F),  but  it  is  so  near  the  top  of  the  stake 
that  if  fruit  canes  are  left  there  is  nothing  to  which  to  tie  them.  If  this 
fruit  wood  is  left  and  pruned  short  we  get  a  vine  like  that  shown  in 
Fig.  8,  which  is  worse  than  an  ordinary  short-pruned  vine. 

This  condition  may  be  avoided  for  a  year  or  two  if,  besides  the  fruit 


FIG. 


Last  stage  of  a  Sultanina  vine  which  has  been  pruned  long  and  the 
canes  tied  up  vertically. 


canes  (C,  C),  we  leave  also  some  short  spurs  of  one  or  two  buds  on  the- 
main  stump.  The  canes  from  these  spurs  will  consist  of  fruit  wood 
and  they  may  be  used  for  fruit  canes  the  following  year.  Unfortu- 
nately these  spurs  are  so  shaded  by  the  foliage  on  the  fruit  canes  that 
they  do  not  always  produce  vigorous  wood,  and  finally  they  fail  to  grow 
at  all. 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


Two  methods  have  been  successfully  used  to  insure  the  growth  of  new 
fruit  wood  every  year  in  a  position  where  it  can  be  utilized.  The  first 
consists  in  bending  the  fruit  canes  into  a  circle,  as  illustrated  in  Fig.  9. 
This  diminishes  the  tendency  of  the  sap  of  the  vine  to  go  to  the  end  of 
the  fruit  canes.  The  consequence  is  that  more  shoots  start  on  the  lower 

parts  of  the  fruit  canes. 
All  the  shoots  on  these 
canes  are  made  weaker 
and  more  fruitful  by  the 
bending,  and  at  the  same 
time  the  sap  pressure  is 
increased  and  causes 
strong  shoots  to  start 
from  the  wood  spurs  left 
near  the  baees  of  the 
fruit  canes.  These  shoots 
are  used  for  fruit  canes 
at  the  following  winter 
pruning,  and  new  wood 
spurs  are  then  left  for  the 
next  year. 

The  tying  and  bending 
of  the  fruit  canes  require 
great  care,  and  repeated 
suckering  and  removal 
of  watersprouts  are 
necessary  to  insure  a 
strong  growth  of  replac- 
ing canes  on  the  \vood 
spurs.  This  method  can 
be  used  successfully  only 
by  skillful  hands. 

The  other  method  re- 
quires some  form  of 
trellis.  The  most  prac- 
ticable trellis  is  a  wire 

FIG.  9.    Showing  method  of  bending  fruit  canes  to  Stretched  along  the  1'OWS 

insure  growth  of  shoots  from  replacing  spurs.  at     about     1^     or     2     feet 

above  the  surface  of  the 

soil.     For  very  vigorous  vines  in  rich  soil  a  second  wire  12  inches  above 
the  first  is  advisable. 

The  pruning  is  the  same  as  for  the  method  just  described.  The  fruit 
canes,  however,  instead  of  being  bent  in  a  circle  and  tied  to  the  stake, 
are  placed  in  a  horizontal  position  and  tied  to  the  wire.  The  horizontal 
position  has  the  same  effect  as  curving  in  promoting  the  starting  of 


BULLETIN  193. 


PRUNING  THE   SULTANINA. 


159 


more  shoots  on  the  fruit  canes  and  the  consequent  production  of  more 
bunches  of  grapes.  At  the  same  time  the  buds  on  the  wood  spurs  are 
forced  to  start,  and  not  being  shaded  they  tend  to  grow  vigorously.  It 
is  best  to  tie  the  shoots  from  the  wood  spurs  in  a  vertical  position  to 


the  stake,  and  they  should  not  be  topped.     This  is  a  modification  of 
what  i«  known  as  the  Guyot  system  of  pruning,  and  is  not  only  theo- 
retically correct,  but  is  easy  to  explain  to  pruners,  and  can  be  carried 
out  much  more  perfectly  than  the  first  method  with  ordinary  labor. 
Whatever  system  of  winter  pruning  is  adopted  with  the  Sultanina, 


160  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

careful  summer  pruning,  suckering,  sprouting,  and  topping  are  neces- 
sary for  the  best  results.  This  variety  has  a  tendency  to  send  out 
large  numbers  of  suckers  from  below  ground  and  watersprouts  from 
the  old  wood.  These  shoots  are  usually  sterile,  grow  vigorously,  and 
unless  removed  in  time  divert  the  energies  of  the  vine  from  the  fruit 
and  fruit  shoots.  Two  or  three  times  during  the  spring  the  vineyard 
should  be  gone  over  carefully  and  all  sterile  shoots  which  are  not 
needed  to  balance  the  vine  or  to  replace  weak  or  missing  arms  should 
be  removed.  This  removal  of  shoots  should  be  done  in  such  a  way 
that  no  shoot  longer  than  12  inches  is  ever  removed.  If  the  water- 
sprouts  are  allowed  to  grow  large  their  removal  weakens  the  vine.  The 
shoots  which  are  to  give  fruit  canes  for  the  following  year  should  not 
be  topped.  The  shoots  from  the  horizontal  fruit  canes  on  the  trellises, 
however,  will  set  their  fruit  better  and  are  less  likely  to  be  broken  by 
the  wind  if  they  are  pinched  or  topped  early. 

No  summer  pruning  of  any  kind  should  be  done  while  the  vines  are 
blossoming,  or  for  a  week  or  ten  days  before  the  blossoms  open. 


STATION    PUBLICATIONS. 

STATION  PUBLICATIONS  AVAILABLE  FOR  DISTRIBUTION. 


REPORTS. 

1896.  Report   of   the   Viticultural    Work   during    the   seasons    1887-93,    with   data 

regarding  the  Vintages  of  1894-95. 

1897.  Resistant   Vines,    their    Selection,    Adaptation,    and    Grafting.      Appendix    to 

Viticultural  Report  for  1896. 

1898.  Partial  Report  of  Work  of  Agricultural   Experiment   Station   for  the  years 

1895-96  and  1896-97. 
1900.     Report  of  the  Agricultural  Experiment  Station  for  the  year  1897-98. 

1902.  Report  of  the  Agricultural  Experiment  Station  for  1898-1901. 

1903.  Report  of  the  Agricultural  Experiment  Station  for  1901-1903. 

1904.  Twenty-second  Report  of  the  Agricultural  Experiment  Station  for,  1903-1904. 

TECHNICAL  BULLETINS— ENTOMOLOGICAL  SERIES. 

Vol.  1,  No.  1 — Wing  Veins  of  Insects. 

No.  2 — Catalogue  of  the  Ephydridae. 

BULLETINS. 

Reprint.  Endurance  of  Drought  in  Soils  of  the  Arid  Region. 

No.  128.  Nature,  Value  and  Utilization  of  Alkali  Lands,  and  Tolerance  of  Alkali. 

(Revised  and  Reprint,  1905.) 

133.  Tolerance  of  Alkali  by  Various  Cultures. 

140.  Lands  of  the  Colorado  Delta  in  Salton  Basin,  and  Supplement. 

141.  Deciduous  Fruits  at  Paso  Robles. 

142.  Grasshoppers  in  California. 
144.  The  Peach- Worm. 

147.  Culture  Work  of  the  Substations. 

148.  Resistant  Vines  and  their  Hybrids. 

149.  California  Sugar  Industry. 

150.  The  Value  of  Oak  Leaves  for  Forage. 

151.  Arsenical  Insecticides. 

152.  Fumigation  Dosage. 

153.  Spraying  with  Distillates. 

154.  Sulfur  Sprays  for  Red  Spider. 
156.  Fowl  Cholera. 

158.  California  Olive  Oil ;   its  Manufacture. 

159.  Contribution  to  the  Study  of  Fermentation. 

160.  The  Hop  Aphis. 

161.  Tuberculosis  in  Fowls.      (Reprint.) 

162.  Commercial  Fertilizers.      (Dec.  1,  1904.) 

163.  Pear  Scab. 

164.  Poultry  Feeding  and  Proprietary  Foods.      (Reprint.) 

165.  Asparagus  and  Asparagus  Rust  in  California. 

166.  Spraying  for  Scale  Insects. 

167.  Manufacture  of  Dry  Wines  in  Hot  Countries. 

168.  Observations  on  Some  Vine  Diseases  in  Sonoma  County. 

169.  Tolerance  of  the  Sugar  Beet  for  Alkali. 

170.  Studies  in  Grasshopper  Control. 

171.  Commercial  Fertilizers.      (June  30,  1905.) 

172.  Further  Experience  in  Asparagus  Rust  Control. 

173.  Commercial  Fertilizers.     (December,  1905.) 

174.  A  New  Wine-Cooling  Machine. 

175.  Tomato  Diseases  in  California. 

176.  Sugar  Beets  in  the  San  Joaquin  Valley. 

177.  A  New  Method  of  Making  Dry  Red  Wine. 

178.  Mosquito  Control. 

179.  Commercial  Fertilizers.      (June,  1906.) 

180.  Resistant  Vineyards. 

181.  The  Selection  of  Seed-Wheat. 

182.  Analysis  of  Paris  Green  and  Lead  Arsenate.     Proposed  Insecticide  Law. 

183.  The  California  Tussock-moth. 

184.  Report  of  the  Plant  Pathologist  to  July  1,  1906. 

185.  Report  of  Progress  in  Cereal  Investigations. 

186.  The  Oidium  of  the  Vine. 

187.  Commercial   Fertilizers.      (January,   1907.) 

188.  Lining  of  Ditches  and  Reservoirs  to  Prevent  Seepage  Losses. 

189.  Commercial  Fertilizers.      (June,  1907.) 

190.  The  Brown   Rot  of  the  Lemon. 

191.  California  Peach  Blight. 

192.  Insects  Injurious  to  the  Vine  in  California. 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


CIRCULARS. 

No.  1.  Texas  Fever.  No.  23. 

2.  Blackleg.  24. 

3.  Hog  Cholera.  25. 

4.  Anthrax. 

5.  Contagious  Abortion  in  Cows.  26. 
7.  Remedies  for  Insects. 

9.     Asparagus  Rust.  27. 

10.  Reading  Course  in  Economic 

Entomology.      ( Revision. ) 

11.  Fumigation  Practice.  28. 

12.  Silk  Culture. 

13.  The  Culture  of  the  Sugar  Beet. 

15.  Recent  Problems  in  Agriculture.  29. 

What  a  University  Farm  is  For. 

16.  Notes  on  Seed-Wheat. 

17.  Why     Agriculture     Should     be 

Taught  in  the  Public  Schools. 

18.  Caterpillars  on  Oaks.  30. 

19.  Disinfection  of  Stables.  31. 

20.  Reading   Course   in   Irrigation. 

21.  The  Advancement  of  Agricultural 

Education.  32. 

22.  Defecation    of    Must    for    White  33. 

Wine. 


Pure  Yeast  in  Wineries. 

Olive  Pickling. 

Suggestions  Regarding  Exam- 
ination of  Lands. 

Selection  and  Preparation  of 
Vine  Cuttings. 

Marly  Subsoils  and  the  Chlo- 
rosis or  Yellowing  of  Citrus 
Trees. 

A  Preliminary  Progress  Report 
of  Cereal  Investigations, 
1905-07. 

Preliminary  Announcement  Con- 
cerning Instruction  in  Prac- 
tical Agriculture  upon  the 
University  Farm,  Davisville, 
California. 

White  Fly  in  California. 

The  Agricultural  College  and  Its 
Relationship  to  the  Scheme  of 
National  Education. 

White  Fly  Eradication. 

Packing  Prunes  in  Cans.  Cane 
Sugar  vs.  Beet  Sugar. 


Copies  may  be  had  on  application  to  DIRECTOR  OF  EXPERIMENT  STATION,  Berkeley,  Cal. 


UNIVERSITY   OF  CALIFORNIA   PUBLICATIONS. 

COLLEfiE  OK  AGRICULTURE. 

AGRICULTURAL  EXPERIMENT  STATION, 

BERKELEY,  CALIFORNIA. 


THE 

CALIFORNIA  GRAPE  ROOT-WORM 


BY    H.  J.  QUAYLE. 


BULLETIN    No.    195. 

(Berkeley,  (Jal.,  July,  1908.) 


SACRAMENTO: 

W.    \V.    SHANNON,       !       I       :       :       SUPERINTENDENT    STATE    PRINTING. 

1908. 


BENJAMIN  IDE  WHEELER,  Ph.D.,  LL.D.,  President  of  the  University. 


EXPERIMENT  STATION  STAFF. 

E.  J.  WICKSON,  M.A.,  Director  and  Horticulturist. 

E.  W.  HILGARD,  Ph.D.,  LL.D.,  Chemist. 

W.  A.  SETCHELL,  Ph.D.,  Botanist. 

ELWOOD  MEAD,  M.S.,  C.E.,  Irrigation  Engineer.      (Absent  on  leave.) 

LEROY  ANDERSON,  Ph.D.,  Dairy  Industry  and  Superintendent  University  Farm. 

M.  E.  JAFFA,  M.S.,  Nutrition  Expert,  in  charge  of  the  Poultry  Station. 

C.  W.  WOODWORTH,  M.S.,  Entomologist. 

R.  H.  LOUGHRIDGE,  Ph.D.,  Soil  Chemist  and  Physicist. 

G.  W.  SHAW,  M.A.,  Ph.D.,  Agricultural  Technologist,  in  charge  of  Cereal  Stations. 

GEORGE  E.  COLBY,  M.S.,  Chemist.      (Fruits,  Waters,  Insecticides.) 

RALPH  E.  SMITH,  B.S.,  Plant  Pathologist  and  Superintendent  of  Southern  California 

Pathological  Laboratory  and  Experiment  Station.     Whittier. 
A.   R.  WARD,   B.S.A.,  D.V.M.,   Veterinarian  and  Bacteriologist. 
E.  W.  MAJOR,  B.Agr.,  Animal  Industry. 
H.  M.  HALL,  M.S.,  Assistant  Botanist. 
H.  J.  QUAYLE,  A.B.,  Assistant  Entomologist.     Whittier. 
W.    T.    CLARKE,    B.S.,    Assistant    Horticulturist    and    Superintendent    of    University 

Extension  in  Agriculture. 

JOHN  S.  BURD,  B.S.,  Chemist,  in  charge  of  Fertilizer  Control. 
C.  M.  HARING,  D.V.M.,  Assistant  Veterinarian  and  Bacteriologist. 
H.  A.  HOPPER,  B.S.A.,  Assistant  in  Dairy  Husbandry. 
J.  H.  NORTON,  M.S.,  Assistant  Chemist  in  charge  Fertilizer  citrus  Experiment 

Stattm' 


T.  FHUNT,  BS.,  Assistant  Horticulturist, 

E.  B.  BABCOCK,  B.S.,  Assistant  Plant  Pathologist. 

E.  H.  SMITH,  M.S.,  Assistant  Plant  Pathologist. 

F.  L.  YEAW,  B.S.,  Assistant  Plant  Pathologist. 

H.  J.  RAMSEY,  M.S.,  Assistant  Plant  Pathologist,  )        Southern  California  Patholog- 

C.  O.   SMITH,   M.S.,  "  "  "  f  ical  Laboratory.     Whittier. 
R.  E.  MANSELL,  Assistant  in  Horticulture,  in  charge  of  Central  Station  Grounds. 
RALPH  BENTON,   B.S.,   B.L.,  Assistant  in  Entomology. 

A.  J.  GAUMNITZ,  M.S.,  Assistant  in  Cereal  Investigations. 

RACHAEL  CORR,  M.A.,  Assistant  in  Cereal  Laboratory. 

HANS  C.  HOLM,  B.S.,  Assistant  in  Zymology. 

P.  L.  McCREARY,  B.S.,  Laboratory  Assistant  in  Fertilizer  Control. 

F.  E.  JOHNSON,  B.  L.,  Assistant  in  Soil  Laboratory. 

M.  E.  STOVER,  B.S.,  Assistant  in  Agricultural  Chemical  Laboratory. 

D.  R.  HOAGLAND,  A.B.,  Assistant  in  Agricultural  Chemical  Laboratory. 
CHARLES  FUCHS,  Curator  Entomological  Museum. 

P.  L.  HIBBARD,  B.S.,  Assistant  Fertilizer  Control  Laboratory. 

M.  E.  SHERWIN,  Field  Assistant  in  Agronomy. 

W.  H.  VOLCK,  Field  Assistant  in  Entomology.     Watsonville. 

E.  L.  MORRIS,  B.S.,  Field  Assistant  in  Entomology.     San  Jose. 
J.  S.  HUNTER,  Field  Assistant  in  Entomology.     San  Mateo. 

D.  L.  BUNNELL,  Clerk  to  the  Director. 


JOHN  TUOHY,  Patron,          )  Tulare  Substation     Tulare. 

J.  T.  BEARSS,  Foreman,      f 


University  Forestry  Station,  Chico. 
E.  C.  MILLER,  In  charge,    \ 

ROY  JONES,  Patron,  \  University  Forestry  Station,  Santa  Monica. 

N.  D.  INGHAM,  Foreman,    ]' 

VINCENT     J.     HUNTLEY,     Foreman     of     California    Poultry     Experiment     Station, 
Petaluma. 

The  Station  publications  (REPORTS  AND  BULLETINS),  so  long  as  avail- 
able,  will  be  sent  to  any  citizen  of  the  State  on  application. 


THE  CALIFORNIA  GRAPE  ROOT-WORM. 

(Adoxus  obscurus  Linn.) 
BY  H.  J.  QUAYLE. 


The  California  Grape  Root-worm  is  an  insect  that  attacks  both  the 
roots  and  the  growing  parts  of  the  vine  above  ground.  It  has  been 
known  to  attack  the  leaves  of  the  vine  in  this  State  for  a  good  many 
years,  but  until  a  year  or  two  ago  it  was  unknown  as  a  root  feeder.  It  is 
similar  in  its  life  history  and  mode  of  attack  to  the  well-known  grape 
root-worm  of  the  Eastern  States,  which  is  one  of  the  worst  pests  that  the 
vineyardists  there  have  to  wage  war  against.  Our  species  has  been  doing 
considerable  damage  during  the  past  two  or  three  years,  and  it  promises 
to  be  an  important  enemy  of  the  vine  in  California. 

Early  History  in  Europe. — The  first  account  of  this  insect,  which 
leaves  little  doubt  as  to  its  identity,  was  given  by  Aldrovandi  in  1602. x 
It  is  one  of  the  important  pests  of  the  vine  in  France,  as  is  shown 
by  the  amount  of  literature  on  the  insect  that  has  appeared  in  that 
country.  Pluchi2  in  1732  stated  that  it  passed  the  winter  in  the  ground, 
and  this  is  the  first  suggestion  we  have  of  its  underground  habits, 
although  it  was  not  actually  known  by  this  author  to  feed  upon  the 
roots.  The  first  authentic  observation  on  the  root-feeding  habits  appears 
to  have  been  made  in  1849  by  Demermety,3  who  found  it  feeding  upon 
the  roots  of  vines  in  France. 

It  has  received  rather  careful  attention  from  a  number  of  observers 
in  Europe,  but  probably  the  most  complete  account  is  given  in  Mayet's 
"Insectes  de  la  Vigne. "  It  also  occurs,  as  a  grape  pest,  in  Germany, 
Italy,  and  Algeria,  as  well  as  in  France. 

In  California. — The  first  account  of  this  insect  occurring  on  vines  in 
California,  so  far  as  we  have  been  able  to  find,  is  a  brief  notice  in  the 
1  'Pacific  Rural  Press"  for  May  29,  1880.  It  is  here  stated  that  " every 
spring  for  the  last  few  years  there  have  been  received  specimens  of  a 
dark  colored  beetle  about  one  fifth  of  an  inch  long  which  eats  the  leaves 
of  the  grapevine  until  almost  skeletonized."  It  is  doubtful  from  this 
account  just  what  beetle  is  referred  to,  but  the  description  of  the  beetle 
and  its  work  on  the  leaves,  and  the  time  of  the  year  of  its  occurrence, 

1Des  Insectes,  p.  472. 

2  Spectacle  de  la  Nature ;  Paris. 

3  Jour.  d'Agr.  de  Dijon. 


2  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION. 

suggests  the  root  beetle.  Moreover,  Professor  Wickson  who  was  horti- 
cultural editor  of  the  "Press"  at  the  time,  remembers  that  the  article 
had  reference  to  this  species  as  we  now  know  it,  and  not  to  the  flea-beetle 
with  which  it  has  been  commonly  confused. 

The  first  full  account  of  its  occurrence  in  this  State  appears  in  an 
article  by  Matthew  Cooke1  in  1883.  He  confuses  it  with  the  flea-beetle, 
but  he  gives  it  the  scientific  name  of  Adoxus  vitis,  and  from  his  account 
there  is  no  mistaking  the  insect  to  which  he  refers.  He  states  that 
"it  was  reported  from  at  least  six  of  the  vire-growing  sections  of  the 
State  in  1882,  and  in  1883  was  destroying  the  vines  infested.  One 
vineyard  in  the  vicinity  of  Sacramento  was  damaged  seriously  that 
spring.  Its  mode  of  attack  is  similar  to  that  of  the  steel-blue  flea- 
beetle  (Haltica  chalybea  111.),  and  it  frequently  damages  young  vines 
to  such  an  extent  that  they  die.  It  is  an  insect  enemy  of  the  vine  that 
must  be  eradicated." 

There  is  nothing  said  about  the  life  history  in  this  account,  except 
that  it  attacks  the  vine  in  the  same  way  as  the  flea-beetle.  It  is  also 
given  the  common  name  of  "Imported  Grape  Flea-beetle,"  and  we 
therefore  infer  that  he  knew  nothing  of  its  attacking  the  roots.  Neither 
is  there  anything  in  the  literature  of  the  State  which  has  appeared 
since  that  would  indicate  that  it  is  a  root  feeder. 

Its  economic  status  as  given  by  Cooke  was  based  entirely  on  the 
damage  done  to  the  leaves.  Important  as  that  is,  it  is  really  of  much 
less  consequence  than  the  attack  on  the  roots,  as  is  now  known  to  be 
the  case.  Accounts  of  injury  by  this  beetle  have  appeared  from  time 
to  time  since  in  the  press  of  the  State.  Alexander  Craw2  then  State 
quarantine  officer,  gave  a  short  account  of  the  beetle  in  1897.  He 
described  its  attack  on  the  leaves,  and  figured  a  leaf  showing  the  char- 
acteristic work  of  the  beetle,  but  was  apparently  unaware  of  its  under- 
ground habits. 

Riley  and  Howard3  in  1891  stated  that  "In  Europe  Adoxus  vitis 
is  injurious  to  the  grape,  the  larva?  feeding  on  the  roots  and  the  beetle 
destroying  the  leaves,  whereas  in  America  it  is  only  known  to  attack 
a  wild  plant  (Epttobium).  Mr.  E.  Dupont  has  recently  investigated 
the  subject  of  oviposition  and  finds  that  it  occurs  only  on  the  foliage, 
the  young  larva  afterwards  entering  the  ground.  The  life  history  of 
Adoxus  is  thus  in  conformity  with  that  of  an  allied  species,  Chryso- 
clius  auratus  which  lives  on  Apocynum  and  rosoemifolium.  We  have 
found  the  eggs  on  the  leaves  and  the  larvae  underground  feeding  on 
the  roots.  The  nearest  North  American  allies  of  Adoxus,  viz.,  the 
species  of  Fidia,  also  infest  the  grapevine,  but  their  life  histories  have 

1  Injurious  Insects  of  the  Orchard  and  Vineyard,  1883. 

2  Destructive  Insects,  1897. 

3  Insect  Life,  vol.  Ill,  p.  349. 


BULLETIN  195.  CALIFORNIA  GRAPE  ROOT-WORM.  3 

never  been  investigated. ' '  The  first  actual  observation  on  the  root-feed- 
ing habits  on  the  grape  in  this  country,  so  far  as  we  know,  was  made 
by  Mr.  0.  Butler  of  this  station,  who  found  it  on  the  roots  of  vines  near 
Lodi  in  1905. 

Its  Name. — A  beetle  was  described  in  1602  by  Aldrovandi,1  which 
seems  to  answer  the  description  of  this  species ;  but  it  was  placed  in 
the  wrong  group  by  this  author,  and  it  was  also  before  the  adoption 
of  the  binomial  system  of  nomenclature.  It  has  been  described  under 
two  or  three  different  generic  names  since,  but  the  one  now  adopted  is 
Adoxus,  given  by  Kirby  in  1837. 

Linnaeus  in  1741  described  a  beetle,  to  which  he  gave  the  specific 
name  obscunts.  This  is  now  known  as  Adoxus  obscurus,  and  is  the 
name  that  has  been  applied  to  the  black  form  of  the  beetle  occurring 
in  California  and  elsewhere  in  the  United  States.  Mayet2  states  that 
obscurus  Linn,  is  somewhat  larger  than  vitis,  entirely  black,  and  found 
on  a  plant  (Epilobium)  of  the  marshy  prairies,  sometimes  upon  "trifli" 
clover,  but  never  on  the  vine.  Dr.  Horn3  states  that  the  only  known 
species  of  the  genus  inhabits-  Europe  and  the  northern  part  of  our  own 
continent,  and  that  it  varies  in  a  similar  manner  in  both  regions. 

In  California  it  is  certain  that  both  the  black  and  brown  forms  are 
the  same  species.  Wherever  the  beetle  was  seen  during  the  past  two 
years  the  two  forms  occurred  in  about  equal  numbers,  and  were  found 
interbreeding  in  all  combinations.  A  large  number  of  specimens  of  A. 
vitis  were  kindly  sent  to  us  by  Professor  Valery  Mayet  of  Montpellier, 
France,  and  they  appeared  to  be  identical  with  the  brown  form  occur- 
ring here.  He  also  sent  us  two  specimens  of  A.  obscurus,  saying  that 
these  were  very  rare  and  never  found  on  the  vine,  as  noted  above.  They 
were  slightly  larger  than  the  black  form  occurring  on  the  vine  here. 

On  account  of  the  great  difference  in  food  plants  it  would  appear 
that  the  obscunts  of  France  is  a  distinct  species  from  that  of  vitis;  but 
an  inquiry  into  the  geographical  distribution  of  the  two  forms  seems  to 
indicate  that  it  is  simply  a  case  of  a  dichromatic  species,  with  one  or  the 
other  of  the  two  forms  predominating  in  the  different  regions,  with  the 
exception  of  the  California  vineyards,  where  both  forms  occur  in  about 
equal  numbers. 

On  account  of  priority  the  correct  specific  name  should  be  obscurus 
Linn,  representing  the  black  form,  while  vitis  F.  should  be  applied  to  the 
bi colored  variety. 

In  France  this  insect  goes  by  the  common  name  of  Le  Gribouri  or 
Ecrivain,  the  scrawler  or  writer;  but  since  these  names  are  hardly 

1  Des   Insectes,   1G02. 

2  Insectes  de  la  Vigne,  p.  322,  1890. 
3Amer.   Entomol.    Soc.,    vol.    19,    p.    196. 


4  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

applicable  in  this  country  and  because  of  the  possible  confusion  with 
the  engraver  beetles,  it  does  not  seem  desirable  to  adopt  either  of  these 
as  a  common  name  for  the  insect.  Cooke  gave  it  the  name  of  "Imported 
Grape  Flea-beetle";  but  since  it  is  not  a  flea-beetle  at  all,  this  name  is 
not  warranted.  Since  the  life  history  and  habits  of  this  species  are 
almost  identical  with  those  of  the  Grape  Root-worm  (Fidia  viticida 
Walsh)  of  the  Eastern  States,  and  the  fact  that  it  is,  thus  far  at  least, 
a  grape  pest  in  this  country  only  in  California,  we  have  given  it  the 
common  name  of  California  Grape  Root-worm. 

Distribution. — According  to  Dr.  Horn1  the  obscurus  or  black  form 
occurs  most  abundantly  in  California  and  Nevada  and  one  specimen  has 
been  noted  from  Colorado.  The  vitis  form  extends  from  New  Hamp- 
shire westward  to  the  Lake  Superior  region,  Utah,  Colorado,  and  Wash- 
ington, only  a  few  specimens  coming  from  the  last  three  localities. 
Dr.  Hamilton  in  his  catalogue  mentions  Adoxus  vitis  as  "widely  dis- 
tributed across  the  northern  part  of  the  continent,  extending  north 
on  Mount  Washington,  N.  H.,  to  the  Hudson  Bay  region,  westward  to 
California  and  south  to  New  Mexico;  and  southward  in  the  Atlantic 
States  through  New  York."  A.  L.  Melander,  entomologist  of  the 
Washington  Station,  states  that  there  is  but  a  single  specimen  in  their 
collection  taken  in  the  Grand  Coulee  in  1892.  Professor  Cordley  of  the 
Oregon  Station  writes  that  he  has  no  record  of  its  .occurring  in  that 
state  on  the  grape,  nor  has  Professor  Aldrich  any  record  of  its  occur- 
rence in  Idaho. 

Through  the  kindness  of  A.  L.  Quaintance  of  the  Bureau  of  Ento- 
mology, Washington,  we  are  able  to  give  the  localities  of  obscurus  and 
vitis  occurring  in  the  National  Museum  Collection,  as  follows:  Mount 
Adams  and  Mount  Washington,  N.  H. ;  Marquette  and  Port  Huron, 
Mich.;  numerous  specimens  from  New  York  and  New  Jersey;  Isle 
Royal  and  Michipicoten  Bay,  Lake  Superior;  Colorado  Springs, 
Veta  Pass,  Elk  Park,  and  Garland,  Colorado ;  Bear  Paw  Mountain, 
Mont. ;  Park  City  and  Alta,  Utah ;  Kaslo  and  Bear  Lake,  B.  C. ;  Easton, 
Washington;  Portland,  Oregon;  Placer,  Alameda,  Los  Angeles,  and 
Sonoma,  California ;  and  Bulah,  New  Mexico. 

We  are  indebted  to  Dr.  E.  C.  Van  Dyke,  of  the  California  Academy 
of  Sciences,  for  some  interesting  facts  on  the  distribution  of  Adoxus, 
from  whom  we  quote  as  follows:  "The  various  species  of  its  native 
food  plant,  Epilobium,  is  widely  distributed  over  the  northern  parts  of 
Europe,  Asia  and  North  America.  On  the  Pacific  Slope  the  beetle  is 
found  in  all  of  the  lowlands  of  western  Washington  and  the  northern 
half  of  western  Oregon  and  extends  south  along  the  Cascades  (here 
up  to  near  the  timber  line,  some  specimens  being  taken  at  an  elevation 
of  10,000  feet  on  the  snow  fields  of  Mount  Rainier)  ;  along  the  Sierras  to 

1  Trans.  Amer.  Entomol.  Soc.,  XIX,  p.  198,  1892. 


BULLETIN  195.  CALIFORNIA  GRAPE  ROOT- WORM.  5 

at  least  as  far  south  as  Tulare  County,  California.  This  region,  includ- 
ing also  the  Eastern  States,  with  the  exception  of  the  Sierras  in  Cali- 
fornia, is  occupied  by  the  bicolored  variety  vitis  F.  The  melanotic  form 
or  true  obscurus  L.  has  been  found  besides  in  California,  in  Colorado, 
and  one  specimen,  among  many  thousands  of  the  variety  vitis  F.,  at  Port 
Angeles,  Washington. 

' '  The  insect  is  found  throughout  Siberia,  where  in  the  Amoor  region 
and  around  Lake  Baikal,  the  true  obscurus  L. — according  to  the  cata- 
logue of  L.  Von  Hey  den,  which  clearly  differentiates  the  two  forms — 
is  the  dominant  one,  and  perhaps  as  much  a  race  there  as  it  is  here. 
In  west  Siberia  the  variety  vitis  F.  seems  to  be  the  predominant  one. 
This  peculiarity  of  distribution  is  in  keeping  with  that  of  many  of  the 
other  species  of  beetles  that  are  common  to  both  continents,  the  eastern 
specimens  related  to  the  more  western  of  those  of  the  old  world,  while 
ours  are  more  closely  related  to  those  of  the  highlands  of  southeastern 
Siberia,  etc.,  the  so-called  Japano-Manchurian  region." 

It  appears  then  that  the  obscurus  form  living  upon  its  native  food 
plant  in  the  Sierra  Nevada  mountains  has  transferred  itself  to  the  vine- 
yards, but  here  instead  of  obscurus  occurring  exclusively,  both  obscurus 
and  vitis  occur  in  about  equal  numbers.  The  points  at  which  the  beetles 
were  reported  as  injurious  this  year  from  Merced  to  Marysville,  parallel 
with  the  Sierras,  points  strongly  to  the  fact  that  it  has  come  down  from 
the  mountains  and  established  itself  in  the  vineyards  of  the  valley. 
The  beetles  also  occur  in  the  Sonoma  Valley,  and  this  may  be  accounted 
for  by  the  fact  that  its  native  food  plant  is  also  found  here.  According 
to  Jepson,1  the  fire  weed  (Epilobium  spicatum)  has  been  collected  in 
western  and  middle  California  only  in  Sonoma  County,  near  Guerne- 
ville.  The  distribution  of  this  insect,  with  its  varying  color  forms  in  the 
different  regions  and  its  apparent  transfer  to  cultivated  plants,  present 
an  interesting  biological  problem. 

As  an  economic  species  it  is  widely  distributed  in  Europe,  occurring 
particularly  in  the  vineyard  sections  of  France,  Italy,  and  Algeria. 
Here  in  the  United  States  it  seems  to  have  gained  its  strongest  foothold 
in  California.  According  to  Cooke  it  was  reported  from  six  of  the 
principal  grape  sections  of  the  State  as  far  back  as  1882.  Within  the 
last  two  or  three  years  it  has  been  most  abundant  in  the  Sacramento  and 
San  Joaquin  valleys,  and  in  the  coast  region  near  Sebastopol  and 
Healdsburg. 

Related  Species. — In  the  Eastern  States,  particularly  in  the  grape 
growing  sections  of  Ohio  and  the  Chautauqua  belt  of  New  York,  there 
is  a  similar  insect  called  the  grape  root- worm  (Fidia  viticida  Walsh) 
that  does  very  serious  injury  to  the  vineyards.  This  insect  has  been 

1  Flora  of  Western  and  Middle  California,  p.  329. 


6  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

known  to  occur  in  New  York  since  1866,  and  has  been  a  pest  on  the  vines 
there  since  about  1893. 

This  insect  in  all  essential  respects,  so  far  as  habits  go,  is  similar  to 
the  one  treated  of  in  this  bulletin.  It  is  also  closely  related  entomolog- 
ically,  both  being  members  of  the  same  group  (Emolpini) .  The  common 
Diabrotica,  the  flea-beetles,  the  asparagus  beetle,  and  numerous  other 
leaf  eating  beetles  belong  to  this  same  family. 

Economic  Importance. — While  the  insect  has  occurred  on  vines  in  the 
State  for  the  last  thirty  years  it  seems  not  to  have  spread  so  >  rapidly  as 
might  have  been  expected,  judging  from  the  experience  with  the  same 
insect  in  Europe  and  its  related  species  in  the  Eastern  States.  It  is 
difficult  to  explain  just  what  may  account  for  this. 

Since  the  greater  part  of  the  insect's  life  is  spent  in  the  ground,  it  is 
in  this  stage  that  conditions  would  be  most  likely  to  influence  its 
progress.  Such  conditions  might  be  found '  in  the  kind  of  soil,  the 
cultivation  of  the  soil,  the  variety  of  vines  and  the  great  depth  of  the 
root  systems  in  some  of  our  drier  sections.  Again,  the  true  importance 
of  the  insect's  work  has  never  been  appreciated  in  the  State  hitherto, 
since  it  has  been  known  as  a  leaf  feeder  entirely.  Vines,  therefore,  may 
have  shown  a  general  unthriftiness  due  to  its  attacks,  but  because  the 
root  infesting  habits  of  the  larvse  were  unknown  the  trouble  may  have 
been  assigned  to  other  causes. 

However,  during  the  present  season  in  the  neighborhood  of  Lodi, 
we  have  good  evidence  of  what  injury  the  insect  may  bring  about.  In 
the  particular  vineyard  where  our  studies  were  made,  it  had  been 
noticed  that  something  was  wrong  with  the  vines,  but  just  what  it  was 
had  not  been  determined.  During  the  past  winter  two  or  three  acres 
of  the  vines  which  were  worst  affected  were  dug  up.  The  piece  adjoin- 
ing where  these  vines  were  uprooted  was  badly  infested  during  the 
past  spring  with  a  beetle  with  which  the  .owner  (who  came  into  posses- 
sion of  the  property  a  year  ago)  was  unfamiliar.  The  matter  was 
reported  to  us  and  upon  investigations  it  was  found  to  be  the  root  beetle. 

The  beetles  were  very  abundant  over  a  narrow  strip  in  the  center  of 
the  vireyard  and  had  already  done  considerable  injury  to  the  leaves 
and  other  growing  parts  of  the  vines.  The  men  who  pruned  the  vineyard 
in  the  winter  noticed  that  this  strip  of  vines  had  not  made  the  growth 
that  was  made  by  the  vires  on  either  side.  Fortunately  the  old  stumps 
and  roots  which  had  been  dug  up  had  been  saved  for  fuel,  and  upon 
examination  were  found  to  be  badly  gnawed  by  this  insect.  Some  of 
the  vines  in  the  strip  where  the  beetles  were  abundant  this  year  made 
practically  no  growth  until  late  in  the  season.  The  beetles  were  nearly 
all  killed  on  this  area  this  year,  and  hence  the  vines  became  free  from 
the  larvae  and  started  their  growth  very  late.  On  another  vineyard 


BULLETIN  195.  CALIFORNIA   GRAPE   ROOT- WORM.  7 

near  Lodi  these  beetles  have  been  very  numerous  for  two  or  three  years, 
and  the  owner  estimated  that  his  crop  had  been  reduced  from  one  third 
to  one  half.  These  two  instances  are  comparable  with  what  has  occurred 
over  a  considerable  area  in  the  Eastern  States  on  account  of  the  presence 
of  the  other  species  there. 

Our  species  has  been  observed  in  several  vineyards,  and  doing  consid- 
erable damage  in  1908  where  they  were  not  seen  at  all  in  1907.  This 
may  be  partly  accounted  for  through  the  excessive  rain  in  the  spring 
of  1907  causing  their  temporary  disappearance,  but  there  is  no  doubt 
that  the  insect  is  becoming  more  widely  distributed.  The  station  has 
also  received  more  inquiries  about  the  insect  than  usual  during  the 
season  just  passed. 

The  attacks  of  this  beetle  have  been  credited  with  being  the  cause  of 
the  sunburn  of  the  Tokay  grape.  The  theory  of  those  who  support 
this  view  is  that  the  gnawing  of  the  beetles  on  the  stalks,  pedicels  and 
berries  "poisons  the  sap"  or  injures  the  bunch  mechanically,  and  thus 
induces  the  drying  and  shriveling  of  the  berries. 

The  experiments  and  observations  of  Messrs.  0.  Butler  and  B.  J. 
Wingfield,  at  Florin  in  1905,  indicate  that  the  above-ground  attacks 
of  the  beetle  have  little  or  nothing  to  do  with  causing  sunburn  unless, 
of  course,  there  is  more  or  less  actual  defoliation.  Besides  exposure, 
sunburn  seems  to  be  due  to  several  causes,  tending  to  diminish  the 
vigor  of  the  vine,  and  probably  the  underground  attacks  of  the  beetle 
larvae  are  among  the  most  serious  of  these  weakening  causes. 

The  Soil  It  Infests. — The  typical  soil  in  the  Tokay  grape  section  about 
Lodi  is  a  sandy  loam.  It  is  in  such  soil  that  the  vineyards  mentioned 
above  are  located.  In  another  vineyard,  however,  near  Stockton,  beetles 
were  present  in  considerable  numbers  in  the  black  adobe  soil  character- 
istic of  that  region.  About  Florin,  where  the  soil  is  clayey,  the  insect  is 
also  troublesome. 

Dr.  Felt1  in  speaking  of  the  eastern  root-worm's  preference  for  soil 
says:  "The  depredations  of  this  pest  are  much  worse  and  usually  first 
apparent  in  light,  sandy  or  poor  soils,  and  in  particular  on  gravelly 
knolls.  The  insects  seem  to  thrive  under  such  conditions  and  a  defi- 
cient growth  should  lead  to  immediate  investigation.  Vines  on  rich 
clay  soils  in  our  experience  sustain  comparatively  little  injury  from  this 
pest,  and  this  appears  to  be  the  case  in  Ohio. ' ' 

Preference  for  Varieties. — With  a  view  to  determining  whether 
or  not  seme  varieties  are  resistant  to  the  attacks  of  the  eastern  species, 
the  Cornell  Experiment  Station  secured  roots  of  several  types  of  Ameri- 
can vines,  and  after  grafting  them  on  to  the  standard  varieties  grown 
there,  distributed  them  in  the  infested  districts.  The  work  is  still  in 
the  experimental  stage,  but  it  may  be  promising  as  a  line  of  possible 

1  New  York  State  Museum  Bulletin  59. 


8 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


control  for  such  a  root  infesting  insect.  In  the  same  bulletin  it  is 
stated  that  some  large  vines  of  a  ' '  native  type ' '  growing  along  a  fence 
within  a  few  feet  of  a  badly  infested  Concord  vineyard  suffered  no 
injury,  not  even  the  leaves  being  eaten  by  the  beetles. 

Our  own  observations  on  the  matter  of  resistant  varieties  for  the  root- 
worm  in  California  have  not  been  extensive  enough  to  warrant  drawing 
any  conclusions.  The  infested  vineyards  at  Lodi  are  of  tlje  Tokay  and 
Zinfandel  varieties,  but  since  these  are  the  principal  grapes  grown 
here,  it  proves  nothing.  In  other  sections  many  different  varieties  of 
vines  are  subject  to  attacks  by  this  insect. 

APPEARANCE  AND  DESCRIPTION  OF  THE  STAGES. 

The  Egg. — The  eggs  of  this  beetle  are  small  yellowish  white  objects 


FIG.  1.     A  cluster  of  eggs  as  they  are  found  naturally  on  the 
bark  (enlarged). 


FIG.  2. 


A  single  egg  highly 
magnified. 


which  may  be  found  in  clusters  (Fig.  1)  under  the  old  bark  of  the  vine. 
An  individual  egg  (Fig.  2)  is  about  one  twenty-fifth  of  an  inch  long 
and  somewhat  cylindrical  in  shape,  being  about  one  third  as  broad  as 
long. 

The  Larva. — The  full  grown  larvae  vary  considerably  in  size,  but 
the  larger  number  will  measure  a  little  more  than  a  quarter  of  an  inch, 
as  they  are  found  naturally  in  a  slightly  curved  position.  When  they 
are  straightened  out  they  measure  seven  twentieths  to  eight  twentieths 
of  an  inch.  They  are  white  in  color,  excepting  the  head,  which  is  yellow- 
ish brown,,  with  the  mouth  parts  dark  brown  or  black.  The  arrangement 
of  hairs  is  as  shown  in  figure  3.  The  spiracles  are  indicated  by  a  yellow- 


BULLETIN  195. 


CALIFORNIA  GRAPE  ROOT-WORM. 


ish  spot  or  ring  and  are  easily  visible.  The  proximal  joint  of  the  labial 
palpus  is  as  long  as  the  other  four.  The  antennae  are  short  and  incon- 
spicuous, consisting 
of  three  joints  and 
ending  in  a  couple  of 
peg-like  processes  and 
two  small  spines.  The 
legs  are  covered  with 
hairs  or  setaa  similar 
to  those  on  the  body. 
The  claws  are  long, 
slightly  curved,  and 
dark  brown  in  color. 


FIG.  3.     Larva. 


The  Pupa.  —  The 
pupa  (Figs.  4  and  5) 
is  about  one  fourth  of  an  inch  long  and  about  the  same  length  across  the 
extended  wing  pads.  The  color  is  pure  white,  the  hairs  or  spines  alone 
being  colored  brown.  On  the  head  near  the  prothorax,  extending  trans- 
versely, is  a  row  of  four  spines,  and  behind  this  row  are  four  spines, 
slightly  smaller,  arranged  in  the  form  of  a  quadrangle.  On  the  dorsal 

side  of  the  abdomen 
are  transverse  rows 
of  delicate  hairs.  The 
anterior  and  hind 
femora  are  armed 
with  a  stout  spine. 
On  the  hind  femora 
there  are  also  two 
stout  bristles.  The 
anal  hooks  are  very 
stout  and  broad  at 
the  base,  ending  in  a 
sharp  spine,  curved 
upward  and  tipped 
with  black.  Just 
anterior  to  the  anal 
hooks  on  the  dorsal 
side  is  a  row  of  four 
short  blunt  spine- 
like  tubercles,  each 
ending  in  a  bristle.  On  the  next  anterior  segment  is  a  row  or  six  spines. 
These  are  longer  and  stouter  than  those  on  the  other  segment,  but  end 
in  a  similar  sharp  bristle.  There  are  two  pairs  arranged  on  either  side 


FIG.  4.     Pupa.    Dorsal  view. 


10 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


of  the  dorsal  line,  and  below  these  laterally  is  a  similar  single  spine. 

There  are  also  hairs  or  bristles  extending  farther  laterally. 

The  Beetle.— There 
are  two  forms  of 
the  adult  beetle  oc- 
curring in  the  State, 
one  being  black  in 
color  and  the  other 
mostly  brown. 
There  is  consider- 
able difference  in 
the  size  of  different 
specimens,  and  par- 
ticularly in  the 
sexes  —  the  males 
being  much  smaller. 
On  an  average  they 
will  measure  about 
one  fifth  of  an  inch 
in  length. 

The    black     form 

FIG.  5.     Pupa.    Ventral  view.  (AdoxUS 

Linn.)  is  almost 
wholly  black  in  color. 
The  antennas,  tibia 
and  tarsi,  however, 
in  some  specimens 
merge  into  dark 
brown.  The  entire 
body,  as  well  as  the 
appendages,  are  cov- 
ered with  a  pubes- 
cence'of  short  gray 
hairs. 

The  brown  form 
(Adoxus  vitis  Fab.) 
has  the  elytra,  tibia 
and  basal  half  of 
the  antennae  brown, 
while  the  remaining 
parts  are  black.  It 
is  covered  "  with  a 


FIG.  6.     Adult  of  the  grape  root- worm. 


gray  pubescence  as  is  the  other  form.  The  head  in  both  is  capable  of 
being  well  retracted  into  the  prothorax.  Both  forms  of  the  beetle  are 
about  equally  distributed,  and  interbred  indiscriminately. 


BULLETIN  195.  CALIFORNIA  GRAPE  ROOT-WORM.  11 

LIFE  HISTORY  AND  HABITS. 

The  Egg. — The  eggs  of  this  beetle  are  laid  usually  in  crevices  beneath 
the  inner  layers  of  bark  on  the  old  wood.  They  are  not  confined  to  last 
year's  wood,  as  seems  to  be  the  case  with  its  eastern  ally,  but  are  laid 
anywhere  on  the  stump  of  the  vine  above  four  or  five  inches  from  the 
ground.  '  "With  the  California  system  of  pruning,  there  is  of  course 
little  of  last  year's  wood  left  on  the  vine,  and  the  bark  on  this  is  too 
smooth  to  offer  the  most  suitable  situations  for  egg  laying.  Indeed, 
during  the  past  season  we  found  no  eggs  on  last  year's  wood,  but  all 
on  the  older  part  of  the  stump,  which  was  covered  with  two  or  three 
layers  of  old  bark.  In  some  cases,  where  the  bark  was  in  close  contact 
with  the  wood,  it  was  hard  to  explain  how  the  beetle  got  beneath  the 
two  or  three  layers  to  deposit  its  eggs.  In  nearly  every  case  they  were 
certainly  well  protected  from  most  enemies  and  out  of  reach  of  any 
spray. 

The  eggs  are  laid  in  clusters  of  from  four  or  five  to  twenty-five  or 
thirty;  usually  where  the  smaller  numbers  were  found  the  crevice  in 
which  they  were  deposited  would  not  furnish  room  for  a  larger  number. 
Where  there  was  plenty  of  space  the  number  ranged  from  a  dozen  to 
thirty.  The  most  common  numbers  counted  in  the  many  clusters  exam- 
ined ranged  from  ten  to  twenty. 

The  eggs  in  the  cluster  may  be  irregularly  arranged  or  somewhat  in 
the  form  of  a  concentric  ring,  the  particular  arrangement  depending 
probably  upon  the  space  in  which  they  are  deposited.  Where  there  was 
plenty  of  room  the  eggs  were  sometimes  well  scattered,  extending  over 
a  diameter  of  a  quarter  of  an  inch  or  more.  In  other  cases  a  pretty 
well  defined  concentric  arrangement  was  found.  Occasionally,  a  small 
crevice  would  be  found  with  but  two  or  three  eggs. 

Number. — The  largest  number  we  succeeded  in  .getting  a  single 
female  to  lay  in  our  breeding  cages  was  seventy-nine.  These  were  laid, 
at  three  different  intervals,  extending  over  a  period  of  about  one  month. 
Others  laid  but  a  single  cluster  of  from  fourteen  to  twenty  and  then 
died.  The  same  insect  in  France,  according  to  Mayet,1  lays  in  the 
neighborhood  of  thirty  eggs  either  singly  or  in  patches  on  the  under 
side  of  the  leaves.  This  number  is  probably  simply  an  approximation. 
The  fact,  if  it  is  a  common  occurrence,  that  they  are  laid  on  the  under 
side  of  the  leaves,  is  the  most  striking  difference  between  the  habits 
in  California  and  in  France.  We  have  had  some  eggs  laid  on  leaves 
in  our  breeding  cages  when  there'  was  nothing  else  for  them  to  oviposit 
on,  but  we  never  found  any  indication  of  this  habit  in  the  field. 

From  our  breeding  cage  experiments  and  field  observations  we  are 

1  Insectes  de  la  Vigne,  p.  308. 


12  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

inclined  to  think  that  few,  if  any,  deposit  more  than  three  or  possibly 
four  clusters,  making  a  total  of  not  to  exceed  one  hundred,  or  possibly, 
one  hundred  and  twenty  eggs.  From  fifty  to  seventy-five  will  be  nearer 
the  average.  The  majority  of  the  beetles  in  our  cages  laid  but  a  single 
cluster  of  twenty  or  twenty-five,  but  those  were  under  slightly  un- 
natural conditions  where  there  was  not  a  constant  supply  of  fresh  food. 
A  number  of  females  were  dissected  to  determine  the  number  of  eggs 
in  the  ovaries,  and  these  varied  from  sixteen  to  twenty-four  well 
developed  eggs. 

The  eggs  of  a  cluster  are  very  slightly  glued  together  with  a  sticky 
material.  By  careful  handling  it  is  possible  sometimes  to  take  these  off 
en  masse,  but  the  majority  of  clusters  will  fall  apart  upon  the  slightest 
handling.  The  eggs  of  the  eastern  species  are  said  to  be  covered  with 
a  gummy  material  which  holds  the  entire  mass  securely  together,  but 

with  this  species  we  failed  to 
find  any  that  would  withstand 
any  very  rough  handling  or 
which  could  be  blown  off  the 
vine  in  clusters  by  the  wind. 

Time  Required  to  Hatch. — In 
our  breeding  cages  the  shortest 
time  required  to  hatch  was  eight 
days,  and  the  longest  period 
twelve  days.  This  was  under 
conditions  which  varied  but  little 

FIG.  7.    Larva  of  the  California  grape  root-  from    that    of    the    vineyard,    the 

temperature  being  lower,  if  in 

any  way  different,  especially  in  the  forenoon,  since  the  laboratory  had 
a  west  exposure  away  from  the  morning  sun.  A  large  number  of  eggs 
were  thus  timed  for  the  incubation  period  and  they  all  came  within 
the  limits  stated  above.  This,  of  course,  may  vary  in  warmer  or  colder 
weather,  but  from  ten  to  twelve  days  may  be  taken  as  the  average 
hatching  period.  The  eggs  of  the  same  cluster  were  all  observed  to 
hatch  within  one  day. 

The  Larva. — The  young  larva  upon  hatching  from  the  egg  makes 
its  way  to  the  ground  almost  immediately.  It  may  crawl  to  the 
ground,  as  we  infer  from  finding  them  pretty  well  scattered  down 
the  trunk  of  the  vine,  or  they  may  possibly  in  many  cases  simply  drop 
to  the  ground,  though  this  was  not  actually  observed.  This  seems  to  be 
a  common  habit  with  the  eastern  species,  but  here  in  California  with 
the  short-pruned  vines,  and  consequent  nearness  to  the  ground,  we 
believe  that  most  of  the  larva?  crawl  down  the  trunk.  Young  larva? 
kept  under  observation  in  a  test  tube  filled  with  compacted  soil,  wan- 


BULLETIN  195. 


CALIFORNIA  GRAPE   ROOT- WORM. 


13 


dered  about  looking  for  a  suitable  place  for  entering  the  earth  three 
or  four  hours  before  they  actually  disappeared.  By  the  following 
morning  they  had  gone  about  halfway  down  the  tube,  or  three  inches, 


FIG.  8.    Root  of  a  vine  with  bark  eaten  off  by  root-worm. 

and  before  the  end  of  the  same  day  they  had  burrowed  through  the  six 
inches  of  soil  in  the  tube. 

As  soon  as  the  larvae  reach  the  roots  of  the  vine  they  begin  feed- 
ing, and  it  is  generally  the  smaller  rootlets  that  are  first  attacked, 


FIG.  9.     Stem  leaf  and  fruit  eaten  by  root  beetle. 

although  we  have  found  young  larvae  around  roots  of  considerable  size. 
These  smaller  roots  may  be  eaten  off  entirely.  The  larger  roots  are 
injured  by  the  larvae  gouging  out  long  strips  of  the  bark,  which  some- 
times take  almost  any  direction,  but  on  the  roots  of  medium  size  these 


14  UNIVERSITY   OP   CALIFORNIA EXPERIMENT   STATION. 

strips  are  usually  eaten  out  in  a  direction  parallel  with  the  axis  of  the 
root,  or  in  a  spiral  direction.  The  "frass"  or  eaten  bark  is  left  in  their 
paths  and  is  characteristic  of  their  injury.  The  furrows  made  are  from 
one  tenth  to  one  fifth  of  an  inch  wide,  and  in  cases  of  severe  injury 
all  the  bark  may  be  eaten  away  from  the  roots. 

This  feeding  is  continued  from  the  time  they  hatch  in  the  spring 
until  the  vine  becomes  dormant  in  the  fall.  By  September  1st  some 
of  the  larvae  were  found  nearly  full  grown,  while  others  were  not  more 


FIG.  10.     Grape  leaf  showing  characteristic  work  of  the  beetle. 

than  half  grown.  In  the  case  of  the  latter,  their  growth  is  completed 
by  feeding  during  the  following  spring,  which  accounts  for  some  of  the 
larvae  being  found  as  late  as  the  last  of  May.  The  first  observed  appear- 
ance of  the  young  larvae  in  the  Lodi  section  in  1907  was  on  May  30th, 
this  being  about  a  month  after  the  first  appearance  of  the  beetles. 

The  larvae  were  found  as  far  down  as  two  and  a  half  feet,  and  no 
doubt  go  farther  than  this,  since  in  some  of  the  vines  there  were  no 
roots  to  speak  of  nearer  than  a  couple  of  feet  from  the  surface.  The 
larvae  were  found  within  a  radius  of  fifteen  inches  from  the  main  central 
root,  and  no  doubt  the  majority  occur  within  a  radius  of  a  couple  of 


BULLETIN  195. 


CALIFORNIA   GRAPE   ROOT- WORM. 


15 


feet.  They  apparently  remain  dormant  during  the  winter  season, 
changing  to  pupae  the  following  spring.  Some  full  grown  larvae  of  the 
preceding  year  were  found  about  the  roots  as  late  as  May  29th  during 
1907. 

The  Pupa. — The  full  grown  larva  which  has  wintered  over  in  the 
ground  changes  to  the  pupa  in  the  early  spring.  The  larvae  upon  reach- 
ing maturity  ascend  toward  the  surface  for  pupation.  The  pupae  taken 
this  past  season  were 
found  at  a  depth  vary- 
ing from  four  to  eight 
inches  below  the  sur- 
face. The  depth  de- 
pends somewhat  upon 
the  amount  of  mois- 
ture near  the  surface. 
Those  found  nearer  the 
surface  were  taken 
from  where  there  was 
considerable  moisture 
to  within  two  or  three 
inches  from  the  sur- 
face. The  pupae,  being 
covered  with  a  delicate 
white  skin,  require  a 
fairly  moist  soil  to  pre- 
vent them  from  drying 
or  shriveling  up.  We 
met  with  this  difficulty 
of  drying  with  some  of 
the  pupae  taken  to  the 
laboratory. 

About  two  weeks  is 
required  for  the  devel- 
opment of  the  insect  in 
the  pupa  stage.  The  first  adult  beetles  seen  in  1907  and  1.908  were  dis- 
covered about  May  1st,  so  that  pupation  must  have  begun  about  the 
middle  of  April.  The  insect  may,  however,  remain  in  the  pupa  stage 
for  a  month  or  more. 

The  pupa  simply  rests  in  a  little  cell  hollowed  out  by  the  larva, 
and  any  disturbance  of  the  earth  is  very  likely  to  break  this  cell  and 
expose  the  pupa,  which  on  account  of  its  delicate  structure  will  usually 
succumb  to  such  treatment. 
2— BULL.  195 


FIG.  11. 


Tip  of  a  shoot,  with  the  leaves,  stem,  petioles  and 
pedicels  attacked  by  the  root  beetle. 


16 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


The  Beetle. — The  adult  beetle,  into  which  the  pupa  in  its  cell  in  the 
ground  transforms,  emerges  from  the  ground  and  begins  to  attack  the 
growing  parts  of  the  vine  above  ground.  For  the  greater  part  of  the 
season  the  insect  has  been  a  root  feeder,  but  having  completed  its  early 
stages  underground,  it  comes  to  the  surface  to  feed  for  a  brief  time, 
to  lay  its  eggs,  and  then  dies.  The  beetle  as  it  comes  from  the  ground 
is  somewhat  lighter  in  color,  but  upon  exposure  to  sun  and  light  its 

chitinous  covering 
soon  becomes  darker 
in  color  and  more 
rigid  in  texture. 

The  time  of  ap- 
pearance of  the  first 
beetles  during  the 
years  1907  and  1908 
at  Lodi  was  May 
1st.  They  may  con- 
tinue to  emerge 
until  June  1st  and 
possibly  later,  al- 
though the  greater 
number  of  the  beetles 
came  out  in  1907 
and  1908  during 
the  first  half  of 
May.  It  has  been 
stated  that  a  few 
larvae  and  pupae 
were  taken  on  May 
29th,  which  would 
indicate  that  a  few 
belated  beetles  may 
not  appear  before 
the  middle  of  June. 


FIG.  12.     A  cluster  of  grapes  badly  gnawed  by  the  root  beetle. 


The  beetles  were  most  numerous  on  the  vines  this  season  about  the 
middle  of  May.  In  the  latter  part  of  May  they  begin  to  disappear 
and  by  the  last  of  June  are  practically  all  gone. 

The  beetles  soon  begin  their  work  on  the  vine  by  feeding  upon  the 
leaves.  They  are  nearly  always  found  on  the  upper  surface.  In  feed- 
ing they  eat  out  chain-like  strips  from  the  leaves  (Fig.  10),  these  slits 
being  about  one  twentieth  of  an  inch  wide  and  from  a  quarter  to  three 
quarters  of  an  inch  long.  Sometimes  the  framework  of  the  tissues  is 
left,  making  a  skeletonized  effect,  though  often  the  entire  substance  is 


BULLETIN  195. 

eaten  away.  This 
gives  the  leaf  a 
lace-like  effect,  the 
parts  left  in  cases 
of  bad  injury  be- 
ing held  together 
by  mere  threads. 

The  beetle  also 
gouges  out  strips 
of  the  bark  of  the 
tender  shoots  in 
the  same  manner 
as  it  works  on  the 
leaves  (Fig.  11). 
Sometimes  the 
shoot  is  thus 
gouged  out  all  the 
way  around  and 
turns  brown  in 
color.  This  loss  of 
bark  or  covering 
interferes  consid- 
erably with  the 
conveyance  of 
nourishment  to  the 
fruit  and  growing 
tip.  The  petioles 
of  the  leaf  are 
similarly  attacked, 
as  are  also  the 
pedicels  of  the 
berry ;  and  the 
pedicels  being  of  a 
small  size,  a  few 
gougings  around 
them  will  cause  the 
berry  to  dry  up. 

The  berry  itself 
does  not  escape  the 
attacks  of  this 
beetle,  and  in  July 
berries  may  be  seen 
that  are  cracked 


CALIFORNIA  GRAPE  ROOT- WORM. 


17 


t 


ft  f 
t  t  t 


FIG.  13.     The  work  of  the  beetle  on  the  berries. 


FIG.  14.     A  vine  stunted  in  growth  through  injury  to  the  roots  by 
the  California  grape  root-worm.    Photographed  June  6, 1907. 


18  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

open  or  gouged  out  on  one  side  (Figs.  12,  13),  and  the  growth  inter- 
fered with  as  a  result  of  an  attack  of  these  beetles  in  May  or  June. 
The  beetles  may  continue  to  feed  for  a  month  or  more.  After  feeding 
a  couple  of  weeks  egg  laying  begins,  and  this  takes  place  at  intervals 
of  a  week  or  two,  when  the  clusters  of  eggs  are  deposited  as  already 
indicated. 

The  beetles  are  very  easily  jarred  from  the  vine  upon  the  slightest 
disturbance,  and  fall  to  the  ground  "playing  'possum"  and  remain 
quiet  for  a  short  time,  but  soon  become  active  again  when  left  undis- 
turbed. This  habit  of  readily  dropping  to  the  ground  offers  a  means 
of  controlling  the  insect  in  this  stage.  The  beetles  fly  around  but 
little,  and  will  usually  be  found  in  the  immediate  vicinity  in  which 
they  emerged.  The  vineyards  which  were  under  observation  showed 
that  the  great  bulk  of  the  beetles  were  confined  to  a  comparatively  small 
area,  and  reports  from  the  owners  indicated  that  they  had  been  present 
in  these  spots  for  several  years. 

In  the  case  of  some  vineyards,  according  to  statements  made  by  the 
owners,  these  beetles  have  been  present  for  a  good  many  years.  In 
such  cases  as  these  there  seems  to  have  been  some  factor  in  keeping 
them  from  becoming  excessive  and  destroying  the  vines.  In  one  vine- 
yard near  Lodi,  where  the  beetles  are  said  to  have  been  present  for 
many  years,  they  have  become  especially  abundant  only  during  the 
last  year  or  two.  During  this  period  they  have  also  spread  more 
rapidly,  and  since  it  has  become  known  that  they  feed  upon  the  roots 
as  well  as  the  leaves  the  growers  have  begun  to  realize  their  importance, 
and  remedial  measures  will  be  undertaken  against  the  insects. 

CONTROL  MEASURES. 

Natural. — Probably  the  most  important  factor  in  the  way  of  climatic 
control  of  this  insect  would  be  unusual  rainfall  during  the  winter 
season.  During  the  winter  of  1907,  which  was  a  very  exceptional 
one,  large  areas  were  covered  with  water  which  hitherto  were  unknown 
to  have  been  flooded.  Where  this  exceptional  amount  of  moisture  pre- 
vailed and  vineyards  were  covered  for  a  couple  of  weeks,  there  were 
very  few  beetles  during  the  following  season.  Except  in  one  or  two 
cases,  however,  we  were  not  aware  of  the  fact  that  beetles  had  occurred 
in  those  situations  in  previous  years.  But  they  were,  nevertheless, 
present  again  in  1908. 

Aside  from  excessive  moisture  in  the  soil,  there  is  little  in  the  way 
of  climatic  control  that  will  aid  in  the  fight  against  the  insect,  unless  it 
would  be  in  some  condition  that  would  be  conducive  to  the  development 
of  a  fungus  affecting  the  adult  beetle.  In  our  interior  California 
weather,  however,  of  May  and  June  there  is  little  hope  of  anything 


BULLETIN  195.  CALIFORNIA  GRAPE  ROOT-WORM.  19 

very  effective  appearing  as  dependent  primarily  upon  moist  weather. 
The  fact  that  the  eggs  of  this  beetle  are  very  securely  hidden  away 
beneath  one  or  more  layers  of  bark  affords  little  opportunity  for  them 
to  be  attacked  in  any  large  manner  by  parasitic  or  predatory  insects. 
The  young  larva  is  for  a  brief  period  (from  the  time  of  hatching  until 
it  enters  the  ground)  more  or  less  exposed  to  the  attacks  of  enemies, 
but  the  interval  is  generally  too  short  to  allow  of  very  great  destruction. 
Once  in  the  ground — where  it  remains  for  the  greater  part  of  the  year — 
it  is  pretty  safe  from  most  enemies.  About  the  only  thing  likely  to 
attack  the  larva  here  would  be  the  predaceous  ground  beetles.  None 
of  these  were  actually  observed  attacking  them  during  the  past  two 
years.  The  larva  is  usually  so  deep  in  the  ground  as  to  be  out  of  reach 
of  most  natural  enemies. 

The  pupa  comes  nearer  to  the  surface  and  is  hence  more  liable  to 
attack.  It  is  probably  in  this  stage  that  the  greatest  mortality  occurs, 
both  from  enemies  arid  from  cultivation  of  the  soil  and  other  opera- 
tions by  man.  In  the  adult  or  beetle  stage,  the  insect  is  directly  exposed 
and  is  likely  to  be  attacked  by  a  large  number  of  enemies,  including 
insects  and  birds. 

ARTIFICIAL    CONTROL. 

Of  the  Egg. — Since  the  eggs  are  secreted  under  one  or  more  layers 
of  bark,  there  is  little  possibility  of  any  spray  or  wash  reaching  them. 
On  account  of  their  small  size  and  the  difficulty  of  finding  the  clus- 
ters, hand .  picking  is  out  of  the  question.  Those  who  believe  in 
stripping  off  the  old  bark  and  spraying  with  bluestone  during  the 
dormant  season,  with  the  primary  object  of  preventing  black  knot, 
will,  incidentally,  inconvenience  these  beetles  by  doing  away  with 
the  more  favorable  situations  for  egg  laying.  This,  however,  can 
not  be  counted  upon  as  very  effective  in  controlling  the  beetle.  The 
eggs  will  be  deposited  in  spite  of  this  treatment,  and  freeing  the  vines 
from  their  loose  bark  will  result  simply  in  rendering  the  eggs  a  little 
more  exposed  to  the  attack  of  enemies. 

Of  the  Larva. — The  matter  of  controlling  any  underground  insect 
is  a  difficult  problem,  and  the  larva  of  this  beetle  is  no  exception  to 
the  general  rule.  Various  remedies  and  schemes  have  been  tested  for 
accomplishing  this  work,  but  the  greater  number  of  them  have  been 
abandoned.  The  problem,  therefore,  is  now  limited  largely  to  control 
by  resistant  stock,  cultivation,  crop  rotation,  or  other  regular  farm 
practices;  but,  with  an  insect  such  as  this,  that  spends  a  portion  of 
its  existence  above  ground,  it  is  not  necessary  to  control  it  in  the  larval 
stage,  since  it  can  be  more  easily  and  effectively  done  in  a  later  stage. 

It  was  suggested  by  some  of  the  growers  that  something  might  be 


20 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


applied  to  the  ground  to  prevent  the  larvae  from  entering,  but  knowing 
the  results  of  the  New  York  experiments1  along  this  line,  we  gave 
little  encouragement  to  the  idea,  and  did  not  repeat  the  experiments. 
Kerosene  emulsion  and  crude  petroleum  were  used  in  New  York,  but 
neither  proved  of  any  practical  value.  The  trouble  with  such  sub- 
stances is  that  they  are  too  readily  absorbed  by  the  dry  soil  and  too 
quickly  evaporated.  Our  California  crude  oil,  which  has  an  asphaltum 
base  (instead  of  paraffine,  as  is  the  case  with  eastern  oils),  would  not 
disappear  so  quickly,  but  few  farmers  would  want  such  a  substance 
mixed  with  their  soil. 


FIG.  15.     At  work  digging  out  larvse  of  the  California  grape  root-worm'two 
and  one  half  feet  beneath  the  surface. 

Of  the  Pupa. — As  heretofore  stated,  the  pupa?  are  found  at  a  depth 
of  from  four  to  eight  inches  below  the  surface.  This,  together  with 
the  fact  that  any  disturbance  of  the  cell  in  which  they  are  resting  will 
generally  prove  fatal,  offers  a  chance  of  doing  something  in  the  way  of 
control  while  in  this  stage.  While  some  of  them  are  beyond  the  depth 
of  the  plow  as  ordinarily  used  about  the  vine,  yet  probably  the  major- 
ity will  be  found  within  about  six  inches  from  the  surface.  They  do 
not  come  up  to  the  dry  soil  to  pupate,  but  remain  just  below  it.  If 
a  shallow  mulch  of  two  or  three  inches  can  be  kept  immediately  around 
the  vines  until  the  insects  are  ready  to  pupate,  this  will  conserve  the 

-1  New  York  State  Museum  Bulletin  59,  p.  77. 


BULLETIN  195. 


CALIFORNIA  GRAPE   ROOT-WORM. 


21 


moisture  just  below  the  mulch  and  encourage  the  larvae  to  come  nearer 
the  surface  to  transform  to  the  pupae.  If  then,  at  the  proper  time, 
just  before  the  beetles  begin  to  emerge,  the  soil,  about  the  vine  is  stirred 
to  a  depth  of  about  six  inches,  no  doubt  a  large  percentage  of  them 
will  be  destroyed.  Another  point,  and  one  which  makes  the  problem 
more  difficult,  is  that  the  pupae  do  not  all  appear  at  once,  but  may  be 
found  for  a  month  or  more.  This  may  make  it  necessary  to  go  over  the 
ground  more  than  once.  However,  probably  the  majority  of  the  beetles 
emerge  at  about  the  same  time  in  the  early  part  of  the  season,  and,  if 
measures  are  taken  against  the  pupae  just  preceding  the  emergence, 
large  numbers  of  them  will  be  destroyed.  If  more  than  one  cultivation 


FIG.  16.     Vines  enclosed  with  mosquito  netting  to  determine  if  beetles  will  emerge  through 

uncultivated  soil. 

is  undertaken  they  should  be  done  at  intervals  not  to  exceed  two  weeks, 
since  the  pupae  will  complete  their  development  within  this  period. 

This  matter  of  deep  cultivation  for  two  or  three  feet  around  the 
vine,  while  not  expected  to  completely  control  the  insect,  will,  never- 
theless, aid  in  its  control.  It  is,  of  course,  of  no  use  unless  done 
at  the  proper  time — when  the  insect  is  in  the  pupal  stage.  The 
proper  time  for  such  cultivation  during  the  past  two  years  at  Lodi 
would  have  been  during  the  last  of  April,  but  this  may  vary  with  the 
season  and  locality. 

It  is  possible  that  in  some  soils  the  destruction  of  the  beetles  before 
they  emerge  from  the  ground  may  be  accomplished  in  another  way. 
In  making  some  experiments  at  Florin,  in  1905,  for  the  determination 
of  the  causes  of  the  sunburn  of  Tokay  grapes,  Mr.  B.  J.  Wingfield 


22 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


found  that  the  beetles  were  unable  to  force  their  way  out  of  the  ground 
when  it  was  covered  with  a  hard,  uncultivated  crust,  such  as  is  left 
after  rain  on  clayey  soils.  Each  of  six  vines  was  covered  on  May  4th 
with  a  cage  of  mosquito  netting.  In  three  of  these  cases  the  netting 
was  tied  tightly  around  the  lower  part  of  the  stem,  as  shown  in  figure  16, 
in  order  to  prevent  the  possibility  of  any  beetles  getting  on  to  the 
above-ground  portion  of  the  vine.  In  the  other  three  cases  the  netting 

was  brought  down 
to  the  ground, 
enclosing  about 
three  square  feet 
of  soil  surface  in- 
side the  cage,  as 
also  shown  in 
figure  16.  This 
enclosed  surface 
remained  unculti- 
vated until  about 
the  middle  of 
July,  when  the 
cages  were  re- 
moved. 

No  beetles  were 
found  at  any  time 
on  any  of  the 
six  enclosed  vines, 
and  no  signs  of 
their  attacks  on 
leaves,  fruit  or 
other  above- 
ground  portions. 
This  is  easily  ex- 
plained in  the 
case  of  the  vines 
which  were  com- 


FIG.  17.     A  single  vine  as  shown  in  figure  16. 


pletely  shielded  from  attack  by  tying  the  netting  around  the  stump ; 
but  in  the  case  of  the  other  vines  which  were  exposed  to  any  beetles 
which  might  emerge  from  the  soil  within  eighteen  inches  from  the 
stump,  the  only  explanation  seems  to  be  that  the  beetles  were  unable  to 
force  their  way  through  the  compacted  surface  crust.  That  the  pupa^ 
and  beetles  were  abundant  in  the  ground  was  shown  by  the  fact  that 
all  the  uncovered  vines  next  to  those  which  were  covered  were  badly 
infested  by  the  beetles  and  showed  abundant  evidences  of  their  attack 
on  all  parts. 


BULLETIN  195.  CALIFORNIA  GRAPE  ROOT-WORM.  23 

The  effectiveness  of  a  method  based  on  this  experiment  would  depend 
largely  on  the  type  of  soil.  Only  a  soil  that  will  form  a  hard,  com- 
pact surface  layer  could  be  utilized  according  to  this  plan. 

We  do  not  know  how  it  would  appeal  to  the  growers  to  leave  three 
or  four  feet  about  the  vine  uncultivated  until  about  the  middle  of  May 
or  possibly  later,  as  would  be  necessary  in  this  case ;  but  if  the  beetles 
were  present  in  large  numbers  and  this  controlled  them,  it  would  pay 
amply.  Again,  showers  of  rain  that  are  apt  to  come  as  late  as  the  mid- 
dle of  May  would  soften  the  soil  and  militate  against  the  method. 

Spraying. — The  adult  or  beetle  eats  away  portions  of  the  leaf  or 
gouges-  out  strips  of  the  surface  of  the  shoots  and  other  growing  parts, 
so  that  a  poison  applied  to  the  vine  will  be  consumed  by  it  in  this  opera- 
tion. The  most  serious  drawback  to  poisoning  is  the  fact  that  beetles 
are  pretty  resistant  to  poisons,  and  considerable  amounts  must  be  con- 
sumed before  the  insects  are  killed.  However,  if  a  strong  arsenical 
spray  is  thoroughly  applied  at  the  beginning  of  the  attack  it  will 
prove  to  be  fairly  successful. 

In  the  experiments  this  season  the  beetles  were  killed  in  from  two  to 
three  days  on  leaves  thoroughly  sprayed  with  lead  arsenate  in  the 
ratio  of  five  pounds  to  fifty  gallons  of  water.  One  pound  of  paris 
green  to  seventy-five  gallons  of  water  also  gave  good  results.  In  the 
case  of  paris  green  a  few  vines  should  be  used  as  a  test  to  determine 
the  maximum  amount  that  is  safe  for  the  foliage,  since  there  is  danger 
of  burning  if  used  too  strong. 

It  is  not  a  very  difficult  matter  to  spray  the  short-pruned  California 
vine  during  the  last  of  April  or  the  first  of  May,  and  thorough  work1 
can  be  done  at  this  time.  The  spray  should  be  applied  mostly  from 
above,  since  it  is  on  the  upper  surface  of  the  leaves  and  shoots  that  most 
of  the  feeding  is  done. 

Jarring. — Since  the  beetle  is  very  readily  jarred  from  the  vine,  this 
offers  one  of  the  most  satisfactory  means  of  controlling  the  insect. 
Generally  it  is  only  those  that  are  in  a  cup-shaped  leaf,  or  in  a  grape 
cluster,  or  in  some  part  of  the  old  wood,  that  will  not  be  disturbed  by 
a  reasonable  jarring. 

This  method  has  the  advantage  of  killing  the  beetles  directly,  before 
egg  laying  is  commenced,  which  may  not  always  be  done  by  means  of 
the  poison  spray.  The  worst  objection  to  the  method  is  that  the  beetles 
may  keep  emerging  from  the  ground  for  three  or  four  weeks,  making 
more  than  one  treatment  necessary.  Fortunately,  however,  these 
attacks  are  generally  confined  to  a  limited  portion  of  the  vineyard,  so 
that  the  problem  is  not  so  difficult  as  it  would  be  were  it  necessary  to 
go  over  the  entire  area. 


24 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


The  sort  of  apparatus  which  was  used  successfully  on  a  badly  in- 
fested vineyard  near  Lodi  this  year  was  the  vine-hopper  cage  shown  in 
figure  18.  This  device  was  constructed  for  capturing  the  vine  hopper, 
and  when  a  nearby  vineyard  became  infested  with  the  beetles  it  was 
used  against  them. 

This  cage  consists  of  .an  ordinary  mosquito  netting  tacked  over  a 
square  framework  of  laths  or  some  other  light  material.  The  essential 
part  of  it  so  far  as  the  beetles  are  concerned  is  the  tray  at  the  bottom. 
This  is  made  of  a  sheet  of  galvanized  iron  turned  up  about  an  inch  at 

the  edges.  The 
crude  oil  which 
is  placed  in  this 
tray  is  fatal  to 
all  insects  falling 
into  it. 

The  V-shaped 
opening  in  the 
tray  permits  the 
cage  to  be  pushed 
on  to  the  vine, 
which  is  bumped 
at  the  same  time 
and  the  beetles 
jarred  off.  A  pad- 
ding of  leather 
is  tacked  on  the 
base  of  the  open- 
ing in  front  of 
the  vine.  The 
opening  may  be 
closed  by  tacking 
two  strips  of  can- 
vas, one  on  each  side,  so  as  to  meet  in  the  center.  These  strips  are  sup- 
ported by  transverse  pieces  of  three-quarter  inch  rubber  tubing,  which 
are  sewed  on  to  the  canvas  beneath.  This  rubber  tubing  supports  the 
canvas  over  the  opening,  and  when  the  cages  are  placed  in  position  it 
gives  way  for  the  base  of  the  vine,  but  immediately  springs  back  again 
through  the  flexibility  of  the  rubber.  Steel  strips  will  answer  the  same 
purpose,  but  the  rubber  is  described  because  it  is  cheaper  and  more 
easily  obtained. 

This  cage  has  the  advantage  of  catching  the  vine  hopper,  which  is 
likely  to  be  present,  with  the  same  operation.  For  the  beetle  alone, 
simply  the  tray  at  the  bottom  may  be  used,  or  the  sides  extended  up 


FIG.  18.     A  cage  used  to  capture  the  beetles  on  the  vine. 


BULLETIN  195.  CALIFORNIA  GRAPE  ROOT- WORM.  25 

and  slightly  outward  with  wire  netting  or  canvas,  to  get  those  that  may 
be  on  the  outer  parts  of  the  vine.  Handles  may  be  attached  to  this, 
so  that  it  can  be  manipulated  without  stooping.  Such  a  cage  can  go 
over  four  or  five  acres  a  day,  and  there  is  little  outlay  save  the  time  of 
the  men  doing  the  work.  Since  the  beetles,  if  taken  in  time,  are  dis- 
tributed over  a  comparatively  small  portion  of  the  vineyard,  it  means 
but  a  day's  work  or  two.  This,  then,  can  be  repeated  three  or  four 
times,  if  necessary,  without  much  expense,  and  the  vines  saved  from 
any  further  ravages  of  the  pest. 

SUMMARY. 

This  insect  has  been  a  destructive  enemy  of  the  vine  in  Europe 
for  many  years,  and  for  several  years  past  it  has  been  doing  considerable 
damage  to  the  grape  in  California.  A  related  native  species  is  an 
important  pest  of  the  vines  in  the  East. 

It  attacks  both  the  roots  and  the  growing  parts  of  the  vine  above 
ground.  From  June  to  May  the  insect  is  in  its  larval  and  pupal  stages 
underground.  During  May  and  June  it  works  on  the  parts  of  the 
vine  above  ground  as  a  beetle. 

Many  of  the  pupa?  may  be  destroyed  by  deep  cultivation  for  a  radius 
of  two  or  three  feet  about  the  base  of  the  vine. 

The  beetles  may  be  killed  by  a  strong  arsenical  spray,  or  by  jarring 
into  crude  oil,  or  otherwise  captured  as  they  are  shaken  from  the  vine. 


26  PUBLICATIONS. 

BIBLIOGRAPHY. 

1(502.  Aldroyandi,  De  Insectes. 

1732.  Pluchi,  Spectacle  de  nature,  Paris. 

1764.  Geoffrey,   Histoire  abregee  des   Insectes  des  environs  de  Paris. 

1804.  Latrielle,    Histoire    naturelle    generate    et   particuliere    des    Crustaces    et   des 

Insectes  (Paris  Hist.  Ins.  1804,  11,  p.  331). 

1819.  Latrielle,   Nouveau  Diet.  d'Histoire  Nat. 

1828.  Touchey,  Bull.  Soc.  Agr.,  Herault,  p.  5. 

1836.  Westwood,  J.  O.     Westwood  on  Insects,  vi,  p.  247. 

1836.  Walckener,  Ann.  de  la  Soc.  Ent.  de  Fr.,  iv,  p.  687  et  seq. 

1841.  Vallot.  Histoire  des  Insectes  Ennemies  de  la  Vigne. 

1842.  Audouin,  Insectes  Ennemies  de  la  Vigne. 

1846.  Guerin-Meneville,  Ann.  Soc.  Ent.  Fr.,  1846,  Ser.  2.  T.  4,  Bull.  p.  35. 

1849.  Demermety,  Quelques  faits  sur  1'Ecrivain,  Jour.  d'Agr.  de  Dijon. 

1862.  Guerin-Meneville,  Rev.  Mag.  Zool.,  14,  pp.  360-4. 

1864.  Baron  Thenard,  Comtes  Rendus  Acad.  Sci.,  6  Novembre,  Vinas,  Le  Gribouri 
(Revue  viticole  de  Dijon). 

1873.  Horvath,    Beitrag  zur   Naturgeschicte   von    Emolpus   vitis,    Ann.    de   la    Soc. 

Imp.  Roy.  Zool.  Bot.  de  Vienne. 

1874.  Lichenstein,  Ann.  Soc.  Ent.  Fr.,  Ser.  5,  T.  iv.  Bull.  p.  228. 

1874.  Girard,  Maurice,  Ann.  Soc.  Ent.  Fr.,  Ser.  — ,  T.  iv,  Bull.  pp.  63  et  140. 

1876.  Lichenstein,  Ann.  Soc.  Ent.  Fr.,  Ser.  5.  T.  v.  Bull.  p.  105. 

1876.  Arviset,  Bull.  Insectol  Agric.,  Paris,  T.  i,  p.  182. 

1876.  Rendu,  V.,  Les  Insectes  Nuisibles  A  FAgriculture,  pp.  106-107. 

1876.  Perris,  Ann.  Fr.,  vol.  6,  pp.  216-217. 

1878.  Valery    Mayet    et    Lichtenstein,    Etude    sur    le    Gribouri,    Ann.    Societe    des 

Agr.    de    France    and   Ann.    Societe    d'Horticulture    et   d'Histoire    nat.    de 
1' Herault. 

1879.  Lichenstein,  Etudes  sur  le  Gribouri  ou  6crivain  de  la  Vigne,  Montpellier,  p.  12. 

1880.  Pacific  Rural  Press,  May  29. 

1881.  Jobert,  C.  R.,  Acad.  Sci.,  Paris,  T.  93,  pp.  975-7,  Jour.  R.  Microsc.,  Ser.  2, 

vol.  ii,  pp.  1-39. 

1882.  Cooke,  Matthew,  Injurious  Insects  of  the  Orchard  and  Vineyard,  p.  194. 

1883.  Kittel,  Correspbl.  Zool.  Min.  Ver.,  Regensburg,  37,  p.  157. 

1887.  Andre,  Metamorphosis  de  1'Eumolpus  vitis.     Le  Naturaliste,  Paris,  pp.  96-98. 

1887.  Oliver,  E.,  Ann.  Soc.  Ent.  Fr.  1887,  Ser.  vi,  T.  7,  p.  128. 

1889.  Le  Progres  Agricole,  x,  No.  37,  pp.  576-8. 

1890.  Mayet,  Les  Insectes  de  la  Vigne,  p.  321. 

1890.  Ricksecker.  L.  E.,  Orchard  and  Farm,  June,  p.  59. 

1891.  Montillot,  Louis,  Les  Insectes  Nuisibles,  pp.  114-6. 
1891.  Craw,  Alexander,  Destructive  Insects. 

1891.  Riley  and  Howard,  Insect  Life,  vol.  iii,  pp.  298  and  349. 

1892.  Horn,  Dr.  Geo.,  American  Entomological  Society,  vol.  19,  p.  196. 

1893.  Rupertsburger,  Wein.  Ent.  Zeit,  xii,  p.  215. 

1896.  Sajo,  K.  Selus,  Wochenschr.  Ent.,  i,  No.  32,  p.  501. 

1897.  Sajo.  K.  Selus,  Wochenschr.  Ent.,  ii,  No.  9,  pp.  129-34. 

1897.  Coste.  Floret  P..  Progres  Agricole  et  Viticole,  Nos.  30,  32,  and  33. 

1908.  Quayle,  H.  J.,  Jour.  EC.  Ent.,  vol.  i,  No.  3,  p.  175. 


PUBLICATIONS.  27 

STATION  PUBLICATIONS  AVAILABLE  FOR  DISTRIBUTION. 


REPORTS. 

189G.     Report    of    the    Viticulture!    Work    during    the    seasons    1887-93,    with    data 

regarding  the  Vintages  of  1894-95. 
3897.     Resistant   Vines,    their    Selection,    Adaptation,    and    Grafting.      Appendix    to 

Viticultural   Report  for  1890. 
1898.     Partial   Report  of  Work  of  Agricultural   Experiment  Station   for  the  years 

1S«.r,-nr,  and  1890-97. 
1900.     Report  of  the  Agricultural  Experiment  Station  for  the  year  1897-98. 

1902.  Report  of  the  Agricultural  Experiment  Station  for  1898-1901. 

1903.  Report  of  the  Agricultural  Experiment  Station  for  1901-1903. 

1904.  Twenty-second  Report  of  the  Agricultural  Experiment  Station  for  1903-1904. 

TECHNICAL  BULLETINS— ENTOMOLOGICAL  SERIES. 

Vol.  1,  No.  1— Wing  Veins  of  Insects. 

No.  2 — Catalogue  of  the  Ephydridse. 

BULLETINS. 

Reprint.  Endurance  of  Drought  in  Soils  of  the  Arid  Region. 

No.  128.  Nature,  Value  and  Utilization  of  Alkali  Lands,  and  Tolerance  of  Alkali. 
(Revised  and  Reprint,  1905.) 

133.  Tolerance  of  Alkali  by  Various  Cultures. 

140.  Lands  of  the  Colorado  Delta  in  Salton  Basin,  and  Supplement. 

142.  Grasshoppers  in  California. 

147.  Culture  Work  of  the  Substations. 

149.  California   Sugar   Industry. 

150.  The  Value  of  Oak  Leaves  for  Forage. 

151.  Arsenical  Insecticides. 

152.  Fumigation  Dosage. 

.53.  Spraying  with  Distillates. 

!  54.  Sulfur  Sprays  for  Red  Spider. 

:  50.  Fowl  Cholera. 

!  58.  California   Olive  Oil  :    its  Manufacture. 

59.  Contribution  to  the  Study  of  Fermentation. 

100.  The  Hop  Aphis. 

101.  Tuberculosis  in  Fowls.      (Reprint.) 

102.  Commercial  Fertilizers.      (Dec.  1,  1904.) 

103.  Pear  Scab. 

104.  I 'on  1  try  Feeding  and  Proprietary  Foods.      (Reprint.) 

105.  Asparagus  and  Asparagus  Rust  in  California. 
100.  Spraying  for   Scale    Insects. 

107.  Manufacture  of   Dry    NVines  in   ITot  Countries. 

108.  Observations  on  Some  Vine  Diseases  in  Sonoma  County. 

109.  Tolerance  of  the  Sugar  Beet  for  Alkali. 

170.  Studies  in  Grasshopper  Control. 

171.  Commercial  Fertilizers.      (June  30.  1905.) 

172.  Further  Experience  in  Asparagus  Rust  Control. 

174.  A  New  Wine-Cooling  Machine. 

175.  Tomato  Diseases  in  California. 

170.  Sugar  Beets  in  the  San  Joaquin  Valley. 

177.  A  New  Method  of  Making  Dry  Red  Wine. 

178.  Mosquito  Control. 

179.  Commercial  Fertilizers.      (June,  1900.) 

180.  Resistant  Vineyards. 

181.  The  Selection  of  Seed-Wheat. 

182.  Analvsis  of  Paris  Green  and  Lead  Arsenate.     Proposed  Insecticide  Law. 

183.  The  California  Tussock-moth. 

184.  Report  of  the  Plant  Pathologist  to  July  1,  1906. 

185.  Report  of  Progress  in  Cereal  Investigations. 
180.  The  Oidium  of  the  Vine. 

187.  Commercial   Fertilizers.      (January,   1907.) 

188.  Lining  of  Ditches  and  Reservoirs  to  Prevent  Seepage  Losses. 

189.  Commercial  Fertilizers.     (June,  1907.) 

190.  The  Brown  Rot  of  the  Lemon. 

191.  California  Peach  Blight. 

192.  Insects  Injurious  to  the  Vine  in  California. 

193.  The  Best  Wine  Grapes  for  California ;   Pruning  Young  Vines ;   Pruning 

the  Sultanina. 

194.  Commercial  Fertilizers   (Dec.  1907). 


28 


PUBLICATIONS. 


CIRCULARS. 

No.     1.  Texas  Fever.  No.  26. 

2.  Blackleg. 

3.  Hog  Cholera.  27. 

4.  Anthrax. 

5.  Contagious  Abortion  in  Cows. 

7.     Remedies  for  Insects.  28. 

9.     Asparagus  Rust. 

10.  Reading     Course     in     Economic 

Entomology.      (Revision.)  29. 

11.  Fumigation  Practice. 

12.  Silk  Culture. 

13.  The  Culture  of  the  Sugar  Beet 

15.  Recent  Problems  in  Agriculture. 

What   a   University   Farm   is  30. 

for.  31. 

16.  Notes  on  Seed-Wheat. 

17.  Why     Agriculture      Should     be 

Taught  in  the  Public  Schools.  32. 

18.  Caterpillars  on  Oaks.  33. 

19.  Disinfection  of  Stables. 

21.  The    Advancement    of    Agricul-  34. 

tural  Education. 

22.  Defecation   of  Must   for   White 

Wine.  35. 

23.  Pure  Yeast  in  Wineries. 

24.  Olive  Pickling. 

25.  Suggestions     Regarding     Exam-  36. 

ination  of  Lands. 


Selection  and  Preparation  of 
Vine  Cuttings. 

Marly  Subsoils  and  the  Chlo- 
rosis '  or  Yellowing  of  Citrus 
Trees. 

A  Preliminary  Progress  Report 
of  Cereal  Investigations, 
1905-07. 

Preliminary  Announcement  Con- 
cerning Instruction  in  Prac- 
tical Agriculture  upon  the1 
University  Farm,  Davisville, 
California. 

White  Fly  in  California. 

The  Agricultural  College  and  Its 
Relationship  to  the  Scheme  of 
National  Education. 

White  Fly  Eradication. 

Packing  Prunes  in  Cans.  Cane 
Sugar  vs.  Beet  Sugar. 

California  State  Farmers'  In- 
stitute at  the  University 
Farm. 

Southern  California  Patholog- 
ical Laboratory  and  Citrus 
Experiment  Station. 

Analyses  of  Fertilizers  for  Con- 
sumers. 


Copies  may  be  had  on  application  to  DIRECTOB  OF  EXPERIMENT  STATION,  Berkeley,  Cal. 


UNIVERSITY  OF    CALIFORNIA    PUBLICATIONS. 

COLLEGE  OF  AGRICULTURE, 

AGRICULTURAL  EXPERIMENT  STATION, 

BERKELEY,  CALIFORNIA. 


GRAPE  CULTURE  IN  CALIFORNIA. 

(ITS  DIFFICULTIES;  PHYLLOXERA  AND  RESISTANT  VINES; 
OTHER  VINE  DISEASES.) 

BY  FREDERIC  T.  BIOLETTI. 

IMPROVED  METHODS  OF  WINE  MAKING. 

BY  FREDERIC  T.  BIOLETTI. 

YEASTS  FROM  CALIFORNIA  GRAPES. 

BY  HANS  C.  HOLM. 


Rupestris   St.   George. 

BULLETIN     No.     197 

(Berkeley,  July,  1908.) 


SACRAMENTO: 

w.  w.  SHANNON,     :     :     :     :     SUPERINTENDENT  STATE  PRINTING. 

1908. 


BENJAMIN  IDE  WHEELER,   Ph.D.,   LL.D.,   President  of  the   University. 


EXPERIMENT  STATION  STAFF. 

E.   J.   WICKSON,   M.A.,  Director  and  Horticulturist. 

E.  W.  HILGARD,  Ph.D.,  LL.D.,  Chemist. 

W.  A.  SETCHELL,   Ph.D.,   Botanist. 

ELWOOD  MEAD,  M.S.,  C.E.,  Irrigation  Engineer.      (Absent  on  leave.) 

LEROY  ANDERSON,  Ph.D.,  Dairy  Industry  and  Superintendent  University  Farm. 

M.  E.  JAFFA,  M.S.,  Nutrition  Expert,  in  charge  of  the  Poultry  Station. 

C.  W.  WOODWORTH,  M.S.,  Entomologist. 

R.  H.  LOUGHRIDGE,  Ph.D.,  Soil  Chemist  and  Physicist. 

G.  W.  SHAW,  M.A.,  Ph.D.,  Agricultural  Technologist,  in  charge  of  Cereal  Stations. 

GEORGE  E.   COLBY,  M.S.,   Chemist,  in  charge  of  Agricultural  Chemical  Laboratory. 

RALPH  E.  SMITH,  B.S.,  Plant  Pathologist  and  Superintendent  of  Southern  California 

Pathological  Laboratory  and  Experiment  Station.      Whittier. 
A.   R.  WARD,   B.S.A.,  D.V.M.,   Veterinarian  and  Bacteriologist. 
E.  W.  MAJOR,  B.Agr.,  Animal  Industry. 
H.  M.  HALL,  M.S.,  Assistant  Botanist. 
H.  J.  QUAYLE,  A.B.,  Assistant  Entomologist.     Whittier. 
W.    T.    CLARKE,    B.S.,    Assistant    Horticulturist    and    Superintendent    of    University 

Extension  in  Agriculture. 

JOHN  S.  BURD,  B.S.,  Chemist,  in  charge  of  Fertilizer  Control 
C.  M.  HARING,  D.V.M.,  Assistant  Veterinarian  and  Bacteriologist. 
H.  A.  HOPPER,  B.S.A.,  Assistant  in  Dairy  Husbandry. 


J.  H.  NORTON,  M.S.,  Assistant  Chemist  in  charge  Fertilizer  } 


Citrus  Experiment 

T.  FOTNTBS,  A^tant  Horticulturist,  Stattm'  Rtmrsid'' 

E.  B.  BABCOCK,  B.S.,  Assistant  Plant  Pathologist. 

E.  H.  SMITH,  M.S.,  Assistant  Plant  Pathologist. 

F.  L.  YEAW,  B.S.,  Assistant  Plant  Pathologist. 

H    J    RAMSEY,  M.S.,  Assistant  Plant  Pathologist,  )        Southern  California  Patholog- 

C.  O.   SMITH,   M.S.,  "  "  )  ical  Laboratory,  Whittier. 
R.  E.  MANSELL,  Assistant  in  Horticulture,  in  charge  of  Central  Station  Grounds. 
RALPH  BENTON,  B.S.,  B.L.,  Assistant  in  Entomology  (Apiculture). 

A.  J.  GAUMNITZ,  M.S.,  Assistant  in  Cereal  Investigations. 

RACHAEL  CORR,  M.A.,  Assistant  in  Cereal  Laboratory. 

HANS  C.  HOLM,  B.S.,  Assistant  in  Zymology. 

P.  L.  McCREARY,  B.S.,  Laboratory  Assistant  in  Fertilizer  Control. 

F.  E.  JOHNSON,  B.  L.,  Assistant  in  Soil  Laboratory. 

M.  E.  STOVER,  B.S.,  Assistant  in  Agricultural  Chemical  Laboratory. 

D.  R.  HOAGLAND,  A.B.,  Assistant  in  Agricultural  Chemical  Laboratory. 
CHARLES  FUCHS,  Curator  Entomological  Museum. 

P.  L.  HIBBARD,  B.S.,  Assistant  Fertilizer  Control  Laboratory. 

M.  E.  SHERWIN,  Field  Assistant  in  Agronomy. 

W.  H.  VOLCK,  Field  Assistant  in  Entomology.     Watsonville. 

E.  L.  MORRIS,  B.S.,  Field  Assistant  in  Entomology.     San  Jose. 
J.  S.  HUNTER,  Field  Assistant  in  Entomology.     San  Mateo. 

D.  L.  BUNNELL,  Clerk  to  the  Director. 


JOHN  TUOHY,  Patron.  )  Tulare  Substation,  Tulare. 

J.  T.  BEARSS,  Foreman,  \ 

J.  W.  ROPER,  Patron,  )  University  Forestry  Station,  Chico. 

E.  C.  MILLER,  In  charge,  \ 


™  University  Forestry  Station,  Santa  Monica. 

N.  D.  INGHAM,  Foreman,    \ 

VINCENT     J.     HUNTLEY,     Foreman     of     California    Poultry     Experiment     Station, 
Petahima. 

The  Station  publications  (REPORTS  AND  BULLETINS),  so  long  as  avail- 
able, will  be  sent  to  any  citizen  of  the  State  on  application. 


GRAPE  CULTURE  IN  CALIFORNIA 


BY  F.  T.  BIOLETTI. 


WORK  OF  THE  STATION. 

The  growing  of  grapes  and  the  industries  based  thereon  are  in  a 
peculiar  sense  Californian.  California  produces,  approximately,  all 
the  raisins,  three  quarters  of  the  wine,  and  a  large  share  of  the  ship- 
ping grapes  of  the  United  States. 

All  these  industries  have  increased  in  importance  with  a  steady  and 
healthy  growth  during  the  last  thirty  or  forty  years,  and  during  the 
last  ten  years  the  increase  has  been  about  75%.  The  new  plantations 
have  been  particularly  numerous  and  extensive  during  the  last  five 
years.  At  present  there  are  over  200,000  acres  of  vineyard  in  the  State, 
and  the  prospects  of  continued  expansion  are  favorable. 

The  growing  of  grapes  has  many  practical  and  sentimental  attrac- 
tions both  for  capitalists  and  small  farmers.  No  other  branch  of 
agriculture  offers  more  certainty  of  steady,  profitable  returns  for 
invested  capital,  and  none  offers  superior  inducements  to  the  owner 
of  a  few  acres  of  land  in  his  effort  to  make  a  pleasant  and  adequate 
living  by  his  own  labor. 

There  is  very  little  of  the  arable  land  of  California  which  is  not 
capable  of  producing  abundant  crops  of  good  grapes,  and  the  future 
output  will  be  limited  only  by  the  demand  and  extent  of  the  market. 

The  very  attractiveness  of  viticulture  and  the  peculiar  suitability 
of  California  for  its  development  involve  dangers  which  must  be 
avoided  if  we  are  to  reap  the  best  results  from  our  advantages.  A 
very  large  proportion  of  our  new  arrivals  and  settlers  engage  in 
some  branch  of  grape-growing.  Most  of  them  have  no  knowledge  of 
the  business,  or  have  preconceived  ideas  which  are  incompatible 
with  our  conditions.  These  conditions  are  so  different  from  those 
of  the  Eastern  States,  and  even  from  those  of  most  of  the  grape-grow- 
ing regions  of  Europe,  that  grape-growers  from  New  York,  Bordeaux, 
Burgundy  or  the  Rhingau  often  fail  to  obtain  better  results  than 
those  who  have  had  no  previous  practical  experience  in  cultivating  the 
vine. 


116  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

In  spite  of  California's  superb  advantages  as  a  grape-growing 
region,  statistics  show  that  our  average  crop  per  acre  is  considerably 
less  than  that  of  Algeria  or  many  parts  of  the  south  of  France, 
and  is  hardly  superior  to  that  of  Burgundy  or  the  Rhingau.  On 
the  other  hand,  the  crops  on  our  best  vineyards,  vineyards  which  are 
handled  properly,  with  due  regard  to  our  special  conditions,  are 
unexcelled  anywhere  in  the  world. 

Two  things,  therefore,  are  urgently  needed.  First,  the  diffusion  of 
special  viticultural  and  enological  knowledge,  and  second,  the  scien- 
tific and  practical  investigation  of  our  peculiar  problems.  Since  1876 
the  Agricultural  College  at  Berkeley  has  given  more  or  less  attention 
to  the  work  of  instruction  and  research  in  viticulture.  At  first  Prof. 
E.  W.  Hilgard  conducted  this  work  almost  single-handed,  and,  as  in 
so  many  other  departments  of  agriculture,  laid  the  solid  foundations 
which  have  contributed  so  much  to  the  improvement  of  our  cultural 
methods.  From  1880  to  1894  the  Viticultural  Commission  did  much 
to  instruct  our  grape-growers  and  wine-makers  in  the  theory  and 
practice  of  their  arts. 

Since  1894  the  only  institution  in  California — in  fact,  in  the  United 
States — which  has  given  special  attention  to  viticulture  has  been  the 
Agricultural  College  and  Experiment  Station  of  the  University  of 
California.  The  work  has  been  carried  on  somewhat  spasmodically, 
owing  to  the  lack  of  regular  appropriations.  At  some  sessions  of  the 
Legislature  provision  has  been  made  for  this  purpose;  at  others  it  has 
been  omitted. 

This  uncertainty  of  support  makes  much  of  the  work  which  ought 
to  be  done  impossible,  and  all  of  it  more  difficult.  Experiments  are 
commenced,  observers  are  trained,  but,  before  the  most  valuable  results 
are  obtained,  the  work  has  to  cease  for  lack  of  funds.  When  a  new 
appropriation  is  made,  new  observers  have  to  be  trained  and  much 
of  the  experiment  work  has  to  be  recommenced.  This  results  in  loss 
of  time  and  efficiency  and  a  much  smaller  output  of  valuable  infor- 
mation than  would  be  possible  if  there  could  be  more  continuity  in 
the  work. 

The  Legislature  of  1905  set  aside  $10,000  for  the  furtherance  of 
viticultural  research  during  the  two  years  commencing  July  1,  1905, 
and  a  considerable  amount  of  progress  has  been  made. 

Besides  the  work  of  investigation  carried  out  under  the  provisions 
of  the  bill  passed  by  the  last  Legislature,  the  regular  viticultural  work 
of  the  University  has  been  carried  on.  This  work  is,  in  the  main  part, 
educational.  It  consists  of  courses  in  grape-growing  and  wine-making 
to  regular  students,  and  short  courses  in  the  same  subjects  to  special 


BULLETIN   197.  GRAPE    CULTURE    IN    CALIFORNIA.  117 

students.  Short  courses  and  viticultural  institutes  have  also  been 
given,  so  far  as  our  time  and  resources  have  allowed,  for  the  benefit 
of  those  actually  employed  in  the  industry. 

The  short  courses  at  Berkeley  to  grape-growers  and  wine-makers 
actively  engaged  in  the  occupations  have  not  been  a  success,  owing  to 
the  small  number  who  have  been  able  to  leave  their  work  long  enough 
to  attend  them.  The  special  viticultural  institutes,  on  the  other  hand, 
have  met  with  a  success  that  is  very  encouraging. 

These  institutes  are  given,  so  far  as  possible,  in  any  viticultural  center 
wherever  a  sufficient  demand  is  manifested  and  the  traveling  expenses 
of  speakers  is  borne  by  the  Farmers'  Institute  appropriation.  They 
last  either  one  or  two  days,  usually  Saturday,  or  Friday  and  Saturday. 
They  are  not  only  confined  strictly  to  viticulture,  but  attempt  to  treat 
only  one  particular  part  of  this  subject.  The  part  chosen  is,  so  far  as 
practicable,  one  of  actual  interest  at  the  season  when  the  institute 
takes  place. 

The  plan  adopted  is  to  accompany  the  lectures  by  practical  demon- 
stration in  the  vineyard.  Two  or  three  hours  in  the  morning  are 
usually  all  that  are  devoted  to  lectures.  The  afternoon  is  spent  in  the 
vineyards,  where  the  ideas  developed  in  the  lectures  are  put  into 
practice.  An  evening  session  is  sometimes  held  to  discuss  the  work 
of  the  day  or  to  treat  some  subject  unsuited  to  field  demonstration. 

An  attempt  is  always  made  to  adapt  the  instruction  to  the  imme- 
diate needs  of  the  locality  and  season,  and  to  the  time  available.  The 
principal  topics  which  so  far  have  been  taken  up  at  these  viticultural 
institutes  are  the  following: 

1.  Starting  a  new  vineyard. 

2.  Pruning  table  grapes. 

3.  Pruning  wine  grapes. 

4.  Pruning  raisin  grapes. 

5.  Pruning  young  vines. 

6.  Oidium  of  the  vine  and  methods  of  control. 

7.  The  phylloxera  of  the  vine. 

8.  Resistant  vines. 

9.  Methods  of  grafting. 

10.  New  varieties  of  grapes. 

11.  Fertilization  of  vineyards. 

Another  important  phase  cf  the  viticultural  activities  of  the 
University  consists  in  an  ever-increasing  correspondence  with  grape- 
growers  and  wine-makers.  Advice  is  given,  suggestions  made,  and, 
where  practicable,  vineyards  and  cellars  are  visited  on  request. 


118  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

Perhaps  the  most  effective  part  of  our  work  at  present  consists  of 
spreading  the  knowledge,  gained  in  the  older  districts  by  veteran 
growers,  among  new  arrivals  and  in  new  districts.  The  repetition  of 
costly  mistakes  is  thus  often  prevented.  More  of  this  work  should  be 
done,  but  the  small  number  of  observers  and  experts  prevents  very 
great  expansion  at  present.  Instead  of  two  or  three  trained  viticultur- 
ists,  the  extent  of  California  and  the  magnitude  of  its  industries  require 
a  dozen.  It  is  to  be  desired  that  an  efficient  expert,  trained  in  the 
science  and  practice  of  grape-growing  and  wine-making,  should  be 
stationed  in  every  large  viticultural  section,  ready  to  advise  all  who 
apply.  The  expense  would  be  compensated  a  hundredfold  by  prevent- 
ing the  frequent  repetition  of  many  costly  mistakes.  Easily  avoidable 
loss  of  hundreds  of  thousands  of  dollars  occur  every  year  through 
ignorance  of  the  best  methods  of  pruning,  grafting,  sulfuring,  ferment- 
ing, packing,  and  all  the  various  operations  of  the  vineyard  and  cellar. 

Men  suitable  for  such  work  in  California  are  difficult  to  find.  It 
requires  an  amount  of  practical  experience  and  technical  training 
which  few  possess.  These  requirements  must,  moreover,  be  coupled 
with  personal  qualifications  of  industry  and  judgment  that  make  their 
possessors  too  valuable  in  other  pursuits  to  make  it  possible  to  retain 
them  unless  they  can  be  assured  continuous  employment  at  good 
salaries. 

Publications  of  the  Viticultural  Department. — In  the  period  of  three 
years  from  January  1,  1905,  to  December  31,  1907,  ten  bulletins  and  five 
circulars  have  been  published  by  the  Viticultural  Department.  These 
represent  the  principal  portion  of  the  work  which  has  been  so  far 
completed  as  to  be  of  immediate  use  to  growers  and  wine-makers. 
Minor  topics  and  incomplete  investigations  are  discussed  shortly  in 
the  present  bulletin. 

PHYLLOXERA. 

This  vine  disease  is  well  established  now  in  nearly  every  large  grape- 
growing  section,  except  those  of  southern  California.  There  are  still 
large  areas  of  vineyard,  however,  in  the  San  Joaquin  and  Sacramento 
valleys  which  have  thus  far  escaped  the  pest.  The  slowness  with  which 
it  has  spread  in  these  regions  is  remarkable  when  we  compare  it  with 
the  rapidity  with  which  vineyards  were  attacked  and  destroyed  in 
Europe,  and  also  in  Sonoma,  Napa,  Santa  Clara  and  other  of  the  coast 
counties. 

There  are  several  obvious  reasons  which  account  in  part  for  this 
slow  extension.  The  various  grape-growing  districts  are  scattered 
throughout  a  wide  plain,  more  or  less  isolated  from  each  other  by 
miles  of  grain  or  pasture  lands. 


BULLETIN   197.  GRAPE    CULTURE    IN    CALIFORNIA.  119 

Many  of  the  vineyards  are  planted  in  sandy  soil,  where  the  progress 
of  the  pest  is  always  slow.  The  natural  power  of  resistance  to  this 
disease  possessed  by  the  Flame  Tokay,  though  not  sufficient  alone  to 
save  it  permanently,  is  no  doubt  a  factor  in  saving  vineyards  of  this 
variety  from  rapid  destruction.  There  seems  some  reason  to  believe 
that  this  variety  under  special  conditions,  when  growing  in  deep, 
rich  soil,  especially  if  somewhat  sandy,  might  be  kept  sufficiently  vigor- 
ous by  careful  cultivation  and  fertilization  indefinitely.  It  would 
be  unsafe  to  trust  to  this  for  immunity,  however,  unless  the  vineyard 
were  situated  where  it  could,  if  necessary,  be  given  a  winter  sub- 
mersion of  three  or  four  weeks  every  few  years. 

It  is  a  mistake  to  suppose,  however,  that  rich  soil  or  ordinary  irriga- 
tion give  any  practical  degree  of  immunity.  Vineyards  in  the  richest 
and  most  copiously  irrigated  regions  of  the  San  Joaquin  Valley  have 
already  been  destroyed  by  the  pest.  What  the  effect  of  alkaline  soil 
has  in  this  respect  is  as  yet  undetermined. 

When  we  have  made  every  allowance  for  the  known  factors  which 
operate  to  delay  the  spread  of  the  Phylloxera  in  the  great  central 
valleys  of  California,  they  do  not  seem  sufficient  to  completely  account 
for  its  slowness.  Even  the  fact  that  the  vineyards  and  wine-growing 
regions  are  widely  separated  by  fields  where  no  vines  grow  is  insiiffi- 
cient  to  account  for  the  slow  spread  of  the  insect,  when  we  know  that 
the  winged  form  may  be  transported  by  the  wind  20  or  30  miles  and 
still  infect  the  vine  on  which  it  is  deposited. 

The  most  plausible  theory  seems  to  be  that  the  winged  form  is 
absent  or  extremely  rare  in  the  interior  of  California.  In  fact,  the 
winged  form  is  produced  most  abundantly  on  American  species  of 
vines,  growing  in  cool,  moist  situations,  and  especially  when  rains 
occur  in  June  and  July.  As  such  conditions  never  occur  in  the 
interior  valleys,  it  is  not  strange  that  the  winged  form  should  be  rare. 
No  record  exists  of  winged  individuals  having  been  seen  in  California 
except  in  the  coast  valleys. 

If  this  theory  is  correct,  the  only  means  the  insect  has  of  spreading 
from  one  vineyard  to  another  in  the-  great  valleys  is  by  crawling  from 
vine  to  vine  or  by  being  carried  on  cuttings  or  roots.  This  makes  the 
delay  of  the  extension  of  the  pest  by  proper  quarantine  measures  par- 
ticularly useful  and  effective. 

These  measures  are  of  two  kinds — those  which  can  be  carried  out 
by  each  grape-grower  himself,  and  those  which  require  the  enforcement 
of  ordinances  by  quarantine  officers.  The  first  are  as  important  and 
more  generally  practicable  than  the  last. 

If  no  winged  insects  occur  there  is  no  danger  of  introducing  the 


120  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

pest  on  cuttings,  for  these  never  carry  the  root  form.  As  their  absence, 
however,  is  not  proved  anywhere,  and  as  cuttings  may  come  from 
regions  where  they  do  exist,  it  is  the  part  of  wisdom  to  disinfect  all 
cuttings  before  planting. 

Disinfection  of  Cuttings. — The  easiest  and  most  effective  method 
for  the  use  of  the  grape-grower  is  by  means  of  bisulfid  of  carbon. 

The  method  of  using  the  bisulfid  is  as  follows:  Place  the  cuttings 
in  a  barrel  or  vat  or  a  box  made  tight  by  means  of  a  thick  coat  of 
paint  or  of  paper  pasted  on  the  inside.  On  top  of  the  cuttings  place 
a  saucer  or  other  shallow  dish,  into  which  to  pour  the  bisulfid  of 
carbon.  An  ordinary  saucer  will  hold  enough  for  a  box  of  27  cubic  feet 
or  a  200-gallon  vat.  For  larger  receptacles  it  is  better  to  use  two 
or  more  saucers.  Deeper  vessels  will  not  do,  as  the  evaporation  is  not 
sufficiently  rapid.  After  pouring  the  bisulfid  into  the  saucer,  cover 
the  box  with  an  oiled  canvas  sheet  or  other  tight-fitting  cover,  and 
allow  to  stand  for  from  forty-five  to  ninety  minutes.  At  the  end 
of  this  time  there  should  be  a  little  of  the  bisulfid  left.  If  it  has  all 
evaporated  this  is  proof  that  insufficient  was  used.  No  flame  lights 
should  be  used,  as  the  liquid  burns  easily  and  the  fumes  form  an 
explosive  mixture  with  the  air.  Lately,  in  Switzerland,  a  cellar  was 
wrecked  and  a  man  killed  by  an  explosion  of  vapors  of  bisulfid  owing 
to  a  neglect  of  this  precaution.  Care  should  be  taken  not  to  spill  any 
of  the  liquid  on  the  cuttings,  as  it  may  kill  them.  It  is  advisable  to 
cut  off  about  half  an  inch  of  the  lower  end  of  the  treated  cuttings 
before  planting,  as  the  vapor  injures  the  open  pith. 

Besides  disinfecting  the  cuttings  in  this  way,  all  the  packing  material 
in  which  they  come  should  be  burnt,  or,  if  valuable,  dipped  in  boiling 
water.  Practically,  it  is  impossible  to  disinfect  rooted  cuttings  by  this 
means  satisfactorily  on  account  of  the  difficulty  of  killing  all  the 
Phylloxera  without  seriously  injuring  the  vine  roots. 

Disinfection  of  Roots. — For  the  disinfection  of  rooted  vines  dipping 
in  hot  water  is  recommended  by  the  best  European  authorities.  The 
roots  should  remain  in  water  at  125°F.  to  130°F.  for  ten  minutes. 
The  same  treatment  may  be  used. for  cuttings.  The  method  has  several 
inconveniences,  however.  Only  small  quantities  can  be  disinfected  at 
one  time,  and  it  requires  great  care  to  see  that,  on  the  one  hand,  the 
heating  is  sufficient  to  kill  the  insects,  and,  on  the  other,  not  sufficient  to 
injure  the  vines.  Experiments  with  this  method  by  the  University 
are  not  promising,  and  many  of  the  rooted  vines  were  killed. 

It  is  probable  that  disinfection  by  means  of  hydrocyanic  gas  as 
practiced  for  nursery  stock  would  be  effective,  but  data  is  lacking  on 
this  point. 


BULLETIN  197.  GRAPE   CULTURE   IN   CALIFORNIA.  121 

Delaying  the  Spread  of  Phylloxera. — When  the  Phylloxera  has 
entered  the  vineyard  it  can  not  be  found  until  it  has  increased  suffi- 
ciently to  kill  or  seriously  weaken  a  vine.  By  this  time  it  has  usually 
spread  to  at  least  several  neighboring  vines.  It  is  usually  hopeless  to 
attempt  to  eradicate  it  in  this  case  without  digging  up  and  destroying 
a  very  large  number  of  vines,  and  even  in  this  case  there  is  no  assurance 
that  other  infected  spots  do  not  exist.  Something,  and  in  some  cases, 
much,  however,  can  be  done  to  delay  its  spread,  and  the  main  part  of 
a  vineyard  may  often  be  preserved  for  many  years  by  proper  measures. 

The  first  thing  to  be  done  when  infection  is  first  discovered  is  to 
dig  up  all  the  dead  and  weakened  vines  and  a  block  surrounding  them, 
including  at  least  three  rows  of  apparently  healthy  vines  on  all  sides. 

These  vines  should  be  all  burned  on  the  spot  or  piled  up  in  the  center 
of  the  infested  block,  sprayed  with  coal  oil,  and  left  for  several  months 
until  the  dry  summer  air  has  certainly  killed  all  the  insects  on  their 
roots.  A  more  effective  method  is  to  treat  the  infested  area  with 
enough  bisulfid  of  carbon  to  kill  both  the  vines  and  the  Phylloxera. 
This  is  done  by  making  holes  with  a  crowbar  12  inches  deep  every 
18  inches  over  the  whole  area.  Into  each  hole  is  poured  1%  ounces 
of  bisulfid  and  the  hole  closed  immediately  with  the  foot.  This  treat- 
ment is  best  applied  in  April  or  May,  after  the  vines  have  started  and 
before  the  ground  becomes  too  dry.  If  any  vines  survive  this  treatment, 
a  new  dose  of  1  ounce  to  the  18  inches  should  be  applied  three  weeks 
later. 

However  carefully  either  of  these  methods  is  carried  out  it  affords 
only  temporary  relief.  In  Switzerland,  Algeria,  and  Germany,  where 
such  methods  have  been  applied  with  the  utmost  strictness  and  under 
military  supervision,  the  spread  of  the  pest  has  been  checked  but  not 
stopped. 

In  any  case,  plows  or  cultivators  should  not  pass  through  affected 
spots  in  the  healthy  parts  of  the  vineyard.  Cultivation  is  one  of  the 
most  effective  means  of  carrying  the  root  insects  from  one  part  of  the 
vineyard  to  another. 

Every  effort  should  be  made  to  discourage  the  introduction  of 
cuttings,  and  especially  of  roots,  from  infested  to  uninfested  districts. 
Wherever  possible  it  is  best  to  obtain  planting  stock  in  the  immediate 
neighborhood. 

Reestablishment  of  the  Vineyard. — When  a  vineyard  becomes  thor- 
oughly infested,  that  is,  when  it  contains  several  scattered,  diseased 
spots,  or  when  10%  to  15%  of  the  vines  are  known  to  be  attacked,  it 
is  useless  to  attempt  to  delay  the  pest  by  these  means.  The  only 


122  UNIVERSITY   OP   CALIFORNIA EXPERIMENT   STATION. 

course  to  be  followed  in  this  case  is  to  cultivate  each  block  as  long 
as  it  produces  paying  crops,  and  then  to  dig  it  up  and  replant  it  with 
bench  grafted  resistants.  It  is  very  bad  policy  to  commence  replanting 
single  vines  or  small  areas  each  year  as  they  fail.  A  young  resistant 
planted  among  old  viniferas  never  gets  the  proper  care,  and  has  no 
chance  to  do  its  best.  Where  this  method  is  adopted,  the  vineyard 
finally  becomes  a  mixed  lot  of  vines  of  various  ages  and  of  various 
degrees  of  unprofitableness.  Replanting  should  be  done  in  regular, 
rectangular  blocks. 

Planting  New  Vineyards. — In  planting  a  vineyard  in  new  soil, 
whether  we  should  plant  grafted  resistants  or  viniferas  on  their  own 
roots  is  to  be  determined  by  local  conditions.  If  there  is  great  likelihood 
of  our  vines  being  attacked  before  they  have  borne  two  or  three  crops 
it  would  be  folly  to  plant  anything  but  resistants.  Hundreds  of  acres, 
in  the  aggregate,  which  have  been  planted  in  Phylloxera-infested 
districts  have  died  before  they  ever  produced  a  crop.  On  the  other 
hand,  if  there  is  a  fair  chance  of  the  vineyard  remaining  uninfested 
for  many  years  it  is  often  safe  to  plant  non-resistants,  and  thus  save 
the  $30.00  to  $40.00  per  acre  extra  which  a  resistant  vineyard  will  cost. 

In  the  counties  of  Marin,  Sonoma,  Napa,  Solano,  Contra  Costa, 
Alameda,  Santa  Clara,  Santa  Cruz,  and  San  Mateo,  where  the  Phylloxera 
is  very  generally  distributed,  it  is  throwing  work  away  to  plant  any- 
thing but  resistant  vines.  The  same  is  true  of  those  districts  in  the 
Sacramento  and  San  Joaquin  valleys  where  the  pest  has  obtained  a 
secure  foothold.  In  any  district  it  is  unsafe  to  plant  non-resistants 
anywhere  within  two  or  three  miles  of  an  infested  vineyard. 


RESISTANT   VINES. 

The  demand  for  information  regarding  Phylloxera-resistant  vines 
becomes  every  day  more  pressing.  The  problems  of  the  adaptation  of 
various  stocks  to  various  soils  and  climates,  of  the  suitability  of 
various  combinations  of  stock  and  scion,  and  of  the  best  methods  of 
grafting  have,  therefore,  been  given  as  much  attention  as  possible. 

Rupestris  St.  George. — Probably  nine  tenths  of  the  resistant  vines 
being  planted  in  California  at  the  present  time  are  Rupestris  St. 
George.  This  is  undoubtedly  a  most  excellent  stock  for  a  large  portion 
of  the  country.  It  is  giving  its  best  results  in  the  interior  valleys  and 
in  the  warmer  parts  of  the  coast  valleys  and  hillsides.  Numerous  cases 
of  partial  failure,  however,  have  been  noted,  which  make  it  certain 
that  for  manv  locations  a  better  stock  is  to  be  found. 


HLTLLETIN  197.  GRAPE    CULTURE    IN    CALIFORNIA.  123 

Most  of  the  cases  of  failure  have  been  reported  from  Sonoma,  Napa, 
and  Santa  Clara  counties.  They  can  nearly  all  be  traced  to  unsuitable 
soil  conditions.  "Where  there  is  an  impermeable  subsoil  (bed  rock  or 
compact  clay)  the  St.  George  usually  fails.  Under  such  conditions,  if 
the  soil  is  dry,  the  vines  make  poor  growth;  if  wet,  the  roots  decay 
and  the  vines  die.  A  very  compact  clay  soil,  even  when  deep,  seems 
unsuited  to  this  variety,  at  least  when  grafted  with  certain  varieties, 
such  as  Emperor  and  Cornichon. 

In  some  cases  the  vines  grow  well,  but  the  crops  are  unsatisfactory. 
This  has  been  noted  only  in  rich  valley  soil  of  the  coast  counties  and 
only  with  certain  varieties.  A  similar  condition  has  often  been  noted 
in  Europe,  but  it  is  usually  easily  overcome  by  longer  pruning  and 
diminishes  with  age. 

A  more  serious  defect  has  been  found  in  some  of  the  cooler  districts. 
Many  varieties  when  grafted  on  St.  George  ripen  from  one  to  two 
weeks  later  than  when  grafted  on  Kip  aria  and  some  other  stocks.  This 
is  due,  probably,  to  the  great  vigor  of  the  stock,  which  keeps  the  vine 
growing  late.  It  is  a  serious  defect  wherever  there  is  difficulty  in 
obtaining  the  desired  amount  of  sugar  in  the  grapes  and  wherever 
late  grapes  are  liable  to  injury  from  the  autumn  rains. 

It  seems  inadvisable,  therefore,  to  plant  St.  George  in  cool  situations, 
on  northerly  slopes  of  the  coast  ranges,  in  localities  close  to  the  coast, 
or  on  shallow,  wet,  very  rich  or  stiff  clay  soils  in  any  locality,  and  to 
use  it  only  on  deep,  permeable  soils  in  the  warmer  districts  and 
locations. 

EXPERIMENTS   WITH    VARIOUS   STOCKS. 

Through  the  courtesy  of  Mr.  J.  K.  Moffit  we  have  been  able  to  take 
some  very  interesting  notes  on  resistant  vines  at  an  experiment  plot  in 
his  vineyard  at  St.  Helena,  Napa  County. 

This  plot  was  planted  in  1900,  under  the  direction  of  the  Experiment 
Station,  with  the  resistant  stocks  and  bench  grafts  which  served  for 
the  experiments  detailed  in  Bulletin  127.  Since  that  time  it  has  been 
looked  after  by  Mr.  B.  Bruck,  the  manager  of  the  vineyard.  The  fol- 
lowing is  a  summary  of  the  notes  taken  in  1905. 

Three  rows  of  25  vines  each  were  planted  with  various  varieties  of 
bench  grafts;  in  one  row  the  stock  being  Rupestris  St.  George,  in 
another  Riparia  Gloire,  and  in  the  third  Riparia  Grande  Glabre.  In 
most  cases  there  were  two  vines  of  each  variety  on  the  same  stock,  in 
some  cases  three,  and  in  some  only  one.  The  results  are,  therefore,  not 
quite  so  convincing  as  if  they  had  been  made  on  a  larger  scale: 


124 


UNIVERSITY   OP   CALIFORNIA EXPERIMENT   STATION. 


Bench  Grafted  Vines.     Planted  in  1900. 

Notes  taken  in  1905. 


SCION. 

Stock. 

Growth  in 
May. 

Crop. 

Remarks. 

Klein  berger  _ 

Rip.  gloire 

Heavy 

Poor 

Much  broken  bv  wind. 

Klein  berger 

St.  George 

Heavy 

None 

Nearly  all  canes  blown  off. 

Sultana 

Rip.  gloire 

Strong 

Good 

Berries  very  large. 

Sultana 

St.  George 

Strong 

Fair 

Berries  smaller  than  on  Rip 

Blue  Portuguese- 
Burger 

Rip.  gloire  
Rip.  gloire. 

Fair  

Good. 
Very  large 

23  pounds  to  one  vine. 

Pinot  Chardon'y 

Rip.  gloire  _  _ 

Fair  __ 

Good. 

Pinot  Chardon'y 
Semillon 

St.  George  
Rip.  gloire 

Very  strong- 
Strong 

Fair. 
Large. 

Palomino 

St.  George 

Very  strong 

Large. 

Valdepenas 

Rip.  gloire 

Very  strong 

Very  large 

22  pounds  to  one  vine. 

Valdepenas 

St.  George 

Very  strong 

Poor. 

Gros  Mansenc 

Rip.  gloire 

Fair 

Heavy. 

Gros  Mansenc 

Rip.  gr.  glabre 

Strong 

Fair. 

Folle  blanche  .._ 
Fresa 

Rip.  gloire  
Rip.  gloire 

Strong  
Fair 

Very  large 
Fair. 

25.5  pounds  to  one  vine. 

Fresa 

Rip.  gr.  glabre 

Strong 

Fair. 

Marsanne 

Rip.  gloire 

Strong 

Fair. 

Marsanne        _  _ 

Rip.  gr.  glabre 

Strong 

Large. 

Marsanne 

St.  George 

Fair          __   . 

Fair. 

Vernaccia 

Rip.  gloire 

Strong 

Large. 

Vernaccia 

Rip.  gr.  glabre 

Very  strong 

Fair. 

Vernaccia 

St.  George 

Strong 

Fair. 

Cornichon 

Rip.  gr.  glabre 

Fair 

Fair. 

Cornichon 

St.  George 

Very  strong- 

Good. 

Aramon 

Rip.  gr.  glabre 

Strong  . 

Good  _ 

22.5  pounds  to  one  vine. 

Mataro 

Rip.  gr.  glabre 

Weak 

Good. 

Mourisco  preto  ._ 
Huasco 

Rip.  gr.  glabre 
Rip.  gr.  glabre 

Very  strong- 
Fair 

Fair. 
Fair 

Much  coulure. 

Sultanina 

Rip.  gr.  glabre 

Very  strong 

Poor. 

Verdot      

Rip.  gr.  glabre 

Very  strong 

Good. 

Barbera 

St.  George 

Very  strong 

Large. 

Beba 

St  George 

Very  strong 

Good 

Berries  very  small. 

Mantuo 

St.  George 

Very  strong 

Fair 

Berries  very  small. 

Franken  Riesl... 
Alicante  Bous.  __ 
Perm  no 

St.  George  
St.  George  
St.  George 

Very  strong- 
Very  strong- 
Very  strong 

Small  
Very  large. 
Large.  • 

Much  coulure. 

In  a  general  way,  all  the  varieties  on  all  stocks  looked  sufficiently 
vigorous,  with  the  exception  of  the  Mataro  on  Riparia  Grande  Glabre. 
The  vines  on  St.  George  were  nearly  always  more  vigorous  than  those 
on  Riparia.  Of  the  two  Riparias  the  Grande  Glabre  seemed  a  little 
the  more  vigorous.  The  relative  standing  of  the  three  stocks  with 
regard  to  vigor  is  indicated  in  the  following  summary: 

Comparison  of  Vigor  of  Vine  on  Various  Stocks. 


VIGOR. 

Number  of  Varieties  on— 

Riparia 
Gloire. 

Riparia 
GrandeGlabre. 

St.  George. 

Verv  strong 

2 
5 
4 
0 

5 
X 

2 
1 

11 
2 
1 
0 

Strong 

Fair 

Weak 

BULLETIN  197. 


GRAPE    CULTURE    IN    CALIFORNIA. 


125 


The  only  variety  which  looked  .very  weak  was  the  Mataro  on  Rip. 
Grande  Glabre.  This  corresponds  with  European  experience  where  it  is 
recommended  to  graft  this  variety  only  on  vinif era  X  American  hybrids, 
such  as  Aramon  X  Rupestris  No.  1  and  Mourvedre  X  Rupestris  1202. 
Where  the  growth  is  marked  "fair"  the  slight  lack  of  vigor  could 
generally  be  ascribed  in  part  to  the  heavy  crop.  Exceptions  to  this 
are  the  Cornichon  and  Huasco  (Muscat  of  Alexandria),  which  not 
only  lacked  vigor  but  also  crop  on  Riparia. 

The  bearing  on  the  various  stocks  may  be  compared  in  the  same 
way  in  the  following  summary: 

Comparison  of  Crops  on  Various  Stocks. 


CROP. 

Number  of  Varieties  on— 

Riparia 
Gloire. 

Riparia 
Grande  Glabre. 

St.  George. 

Very  large 

4 
2 

3 
2 
1 

0 
1 
3 
6 
1 

1 
3 
2 
5 
3 

Large 

Good 

Fair 

Small 

This  is  hardly  a  fair  comparison,  for  the  reason  that  in  most  cases 
the  same  variety  was  not  grafted  on  all  three  stocks.  In  all  cases, 
however,  where  the  same  variety  was  grafted  on  both  Riparia  and 
Rupestris  St.  George,  with  the  exception  of  the  Cornichon  and  Fresa, 
the  vines  on  Riparia  had  larger  crops.  This  is  shown  by  the  following 
comparison : 

Comparison  of  Crops  on  Riparia  and  Rupestris. 


VARIETY. 

Riparia. 

Rupestris 
St.  George. 

Kleinberger 

Poor 

None. 

Sultana 

Good 

Fair. 

Chardonay 

Good  ._     -.     .- 

Fair. 

Valdepefias 

Very  large  -_ 

Poor. 

Gros  Mansenc 

Heavy   

Fair. 

Fresa  

Fair    - 

Fair. 

Marsanne 

Fair  to  large 

Fair. 

Vernaccia 

Fair  to  large 

Fair. 

Cornichon 

Fair 

Good. 

Crop  of  Vines^n— 


It  should  be  noted  that  all  varieties  indiscriminately  were  pruned 
short.  If  those  which  need  long  pruning  when  ungrafted  had  been 
pruned  long,  the  showing  would  undoubtedly  have  been  more  favorable 
to  the  St.  George.  It  is  a  very  valuable  characteristic  of  the  Riparia, 
however,  that  it  enables  us  to  obtain  good  crops  with  short  pruning 


126 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


from  varieties  which  on  their  own  roots  require  long  pruning.  This  is 
exemplified  in  table  on  page  124  by  the  fact  that  of  eleven  varieties  which 
ordinarily  require  long  pruning  eight  varieties  bore  good .  crops  with 
short  pruning  when  grafted  on  Riparia ;  of  seven  long-pruning  varieties 
grafted  on  St.  George,  only  one  bore  good  crops  when  pruned  short. 
This  was  especially  noticeable  with  the  Valdepefias  and  Gros  Mansenc, 
which  bore  very  fine  crops  on  Riparia  Gloire  and  very  little  on  St. 
George. 

The  only  long-pruning  variety  which  bore  well  on  St.  George  was 
the  Barbera.  Of  the  short  pruning  varieties  the  following  bore  well 
on  St.  George:  Palomino,  Alicante  Bouschet,  Perruno,  and  Cornichon. 

The  quality  of  the  grapes  was  in  nearly  all  cases,  where  a  comparison 
was  possible,  better  on  Riparia  stock  than  on  St.  George.  The  grapes 
were  larger  and  sweeter.  The  higher  sugar  content  was,  moreover, 
usually  accompanied  by  higher  acidity,  showing  that  the  grapes  were 
better  developed.  The  following  table  includes  varieties  which  were 
bearing  on  both  Riparia  and  St.  George,  and  shows  very  clearly  the 
superiority  of  the  former  stock  in  regard  to  the  quality  of  the  must : 

Analysis  of  Grapes  from  Grafted  Vines. 

St.  Helena  Plot.     October  6,  1905. 


SCION. 

Stock. 

Sugar. 

Acid. 

Remarks. 

Valdepefias 

Rip.  gloire 

27.5 

.65 

Very  ripe,  a  few  grapes  shriveled. 

Valdepefias 

St.  George 

23.5 

.56 

Crop  very  small. 

Zinfandel 

Rip.  gloire 

26.5 

.92 

Zinfandel 

St.  George  

24.0 

.85 

Many  dried  grapes. 

Aramon  
Mourisco  preto 

Rip.  gr.  glabre-_ 
Rip.  gr.  glabre 

18.2 
23.0 

.96 
.66 

Grapes  small  for  Aramon. 

Blue  PortugUf  se 

Rip.  gloire 

32.2 

.53 

Much  overripe. 

Mataro 

Rip.  gr.  glabre__ 

19.0 

.75 

Gros  Mansenc 

Rip.  gr.  glabre 

26.  7 

1.12 

Gros  Mansenc 

Rip.  gloire 

24.1 

1.20 

Fresa 

Rip.  gr.  glabre  . 

24.0 

.83 

Fresa 

Rip.  gloire 

26.6 

.92 

Alicante  Bouschet 

St.  George 

18.2 

.86 

Barbera 

St.  George 

26.1 

.87 

Marsanne 

Rip.  gr.  glabre 

25.0 

.67 

Marsanne 

Rip.  gloire 

23.3 

.50 

Marsanne 

St.  George 

21.6 

.62 

Chard  on  ay 

Rip.  gloire 

25.0 

.60 

Chardonay  __         
Seniillon 

Rip.  gr.  glabre  __ 
Rip  gloire 

22.8 
26.5 

.87 
.68 

Huasco 

Rip.  gr.  glabre  __ 

27.1 

.64 

Palomino 

St.  George 

26.5 

.55 

Palomino 

St.  George 

29.0 

.45 

Kleinberger 

Rip.  gloire 

22.6 

1.12 

Perruno 

St.  George 

23.4 

.47- 

Franken  Riesling 

St.  George 

26.5 

.59 

Sultana 

St   George 

24.7 

.75 

Sultana 

Rip.  gloire 

24.0 

.75 

Mantuo 

St   George 

27.1 

.39 

Many  small  grapes. 

Beba  
Cornichon 

Rip.  gr.  glabre  __ 
Rip.  gr.  glabre  __ 

20.3 
20.3 

.41 

.77 

Grapes  very  small. 

Cornichon 

St.  George 

18.4 

.65 

Grapes  very  fine. 

BULLETIN  197. 


GRAPE    CULTURE    IN    CALIFORNIA. 


127 


Comparison  of  Composition  of  Grapes  on  Riparia  and  St.  George. 


VARIETY. 

STOCK. 

Riparia  Gloire. 

Riparia  Grande 
Glabre. 

St.  George. 

Valdepenas 

Sugar. 
27.5 
26.5 
24.1 
25.6 
27.5 
23.3 
25.0 
24.0 

Acid. 

.65 
.92 
1.20 
.92 
.84 
.50 
.60 
.75 

Sugar. 

Acid. 

Sugar. 
23.5 
24.0 

Acid. 
.56 

.85 

Zinfandel 

Gros  Mansenc 

26.7 
24.0 

27.6 
25.0 
22.8 

1.12 

.83 
.92 
.67 

.87 

Fresa 

Vernaccia 

24.2 
2L  6 

.61 
.62 

Marsanne 

Chardonav 

Sultana 

24.7 
18.4 

.75 
.65 

Cornichon 

20.3 

.77 

Mean 

25.4 

.80 

24.4 

.86 

22.7 

.67 

These  observations  warn  us  that  we  should  not  hastily  reject  the 
Riparia  as  a  stock.  While  there  have  been  many  failures  on  Riparia, 
these  failures  can  be  traced  to  lack  of  selection  of  the  proper  kind 
of  Riparia  and  to  the  planting  of  Riparia  on  unsuitable  soil.  If  we 
plant  Riparia  Gloire  on  rich,  deep,  loose,  moist  but  well-drained  soil, 
especially  in  the  cooler  districts,  and  avoid  overbearing  by  too  long 
pruning,  we  will  probably  obtain  better  results  than  by  planting 
Rupestris  St.  George  under  the  same  conditions. 

Zinfandel. — A  very  interesting  part  of  the  plot  is  a  series  of  rows  of 
different  stocks  field-grafted  in  1900  with  Zinfandel.  Each  row  con- 
sisted of  about  20  vines.  A  summary  of  the  notes  taken  is  given  in 
the  following  table : 

Notes  on  Zinfandel  Grafted  on  Various  Stocks. 
Vines  5  years  from  grafting.     1905.     St.  Helena. 


STOCK. 

GROWTH. 

Crop. 

Remarks. 

May. 

Aug. 

Sept. 

Rupestris  Martin  

Vigorous. 
Vigorous- 

Vigorous- 
Good 

Good 

Large. 
Good 

Looked    a    little    weak    in 
August,  but  recovered. 
Sugar  24.0,   acid   .85,   many 
dried  grapes. 

More  vigorous  than  3309,  less 
than  St.  George. 
Vines  all  weakly. 
Sugar  26.5,  acid  .92. 
Growth  uneven. 

10114 

Fair  ._ 
Good 

Strong 

Rupestris*  St.  George  _. 
3309 

Good.. 

Fair 

Strong 
Strong 

Fair  .. 
Fair  _ 

Heavy 
Heavy 

Fair  .. 
Good-. 
Large  . 
Good. 
Good. 
Fair. 

101  14 

Vigorous- 
Uneven  __ 
Strong 

Fair  .. 
Weak. 

Viala 

Riparia  Gloire 

Solonis 

Weakg: 
Fair  .  I 
Strong 

Fair  II 
Fair  II 

Fair  .. 
Fair  .. 
Good 

Rupestris  Mission  
Munson 

Riparia  Grande  G  la  bre. 

Fair  II 

It  is  encouraging  to  find  that  our  principal  wine  grape  has  given 
good  results  on  all  the  principal  stocks.  The  vigor  and  bearing  of 
the  vines  on  Riparia  X  Rupestris  3309  and  10114  were  particularly  fine. 


128  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

Mondeuse. — One  of  the  rows  of  this  variety  is  grafted  on  Riparia 
Grande  Glabre  and  is  very  vigorous  and  bearing  good  crops.  About 
600  vines  of  the  same  variety  are  grafted  on  St.  George  and  are  even 
more  vigorous,  but  the  crop  is  uneven.  Owing  to  the  vigor  of  the 
growth  many  canes  were  broken  by  the  wind  in  the  spring,  which 
probably  accounts  for  the  variations  in  bearing.  All  the  vines  show 
a  considerable  amount  of  coulure. 

Semillon  grafted  on  St.  George  made  good  growth,  but  the  crop 
was  unsatisfactory  and  much  coulured. 

Ferrara  on  St.  George  (about  75  vines)  showed  excellent  growth, 
but  only  a  medium  crop  and  much  coulure. 

Tokay  on  St.  George  (50  vines)  was  excellent.  The  vines  were  ex- 
tremely vigorous  and  the  crop  good.  The  bunches  were  not  compact, 
but  were  well  filled.  The  tendency  of  the  stock  to  produce  coulure  in 
this  case  had  resulted  simply  in  a  thinning  of  the  berries,  which  was 
an  advantage. 

St.  Macaire  on  St.  George  has  done  very  well,  being  vigorous,  and 
producing  good  crops  with  short  pruning. 

Bench  Grafts  and  Field  Grafts. — In  starting  this  experiment  plot 
some  of  the  rows  were  planted  with  bench  grafts  and  the  others  with 
rooted  resistants,  which  were  field-grafted  the  following  year.  This 
gives  us  a  good  comparison  of  the  two  methods  as  regards  the  securing 
of  a  good  stand. 

Comparison  of  Bench  Grafting  and  Field  Grafting. 

Qt™i,a  No.  Growing  No.  Failed  by 

5th  Year.  5th  Year. 
FIELD  GRAFTING  (Zinfandel)— 

Rupestris  St.  George. _.  ..  39  =  68%  18  =  32% 

Riparia  X  Rupestris  3309  __  _*36  =  72%  13  =  28% 

Riparia  X  Rupestris  10114  ._  _  42  =  84%  8  =  16% 

Rupestris  Martin _  26  =  55%  21  =  45% 

Vialla_._ ...  16  =  70%  7  =  30% 


Total..  ..,__.  -159  =  70%  67  =  30% 


BENCH  G«A™,O- 

Mondeuse  on  St.  George.  _.  __600  =  98%  14  =    3% 

Tokay  on  St.  George  ____  -  48  =  96%  2=4% 

Ferrara  on  St.  George  ____  ._  70  =  93%  5=7% 


Total 718  =  97%  21=    3% 

As  all  these  vines  were  growing  close  together  on  the  same  kind  of 
soil,  and  under  the  same  management,  the  comparison  speaks  eloquently 
in  favor  of  bench  grafts  as  a  means  of  obtaining  a  perfect  "stand." 


HULLETIN   197.  GRAPE    CULTURE    IN    CALIFORNIA.  129 

EXPERIENCE  OF  GROWERS.      WINE  GRAPES. 

An  attempt  has  been  made  to  collect  the  experience  with  various 
resistant  vines  of  growers  in  various  sections.  The  experience  of  the 
older  vineyards  is  of  little  use,  and,  in  fact,  apt  to  be  misleading,  as 
they  were  nearly  all  grafted  on  unselected  Riparia  and  Rupestris.  The 
stocks  in  the  newer  resistant'  vineyards  are  nearly  all  Rupestris  St. 
George  and  Lenoir,  so  that  the  data  for  comparison  are  meagre.  Some 
of  the  reports  received,  however,  are  interesting  and  are  given  here. 

NAPA   COUNTY. 

B.  Bruck,  St.  Helena. 

Vigor.  Crop. 

Zinfandel  on  St.  George,  7  years  old,  red,  clay,  hill  soil  ...Good  Fair 

Zinfandel  on  Lenoir,  8  years  old,  red,  clay,  hill  soil Good  Fair 

Burger  on  St.  George,  9  years  old,  rich,  dry  soil Good  Large 

Palomino  on  Lenoir,  9  years  old,  rich  loam i Good  Good 

Carignane  on  Lenoir,  8  years  old,  rich  loam Fine  Fine 

Sauvignon  vert  on  Riparia,  14  years  old,  rich  loam__         __Fine  Fine 

Sauvignon  vert  on  St.  George,  5  years  old,  rich  loam Fine  Fair 

Johannisberger  on  Riparia,  10-14  years  old,  loamy  soil Fine  Fair 

Johannisberger  on  St.  George,  6  years  old Strong  Poor 

Tokay  on  St.  George,  7  years  old,  heavy  soil Good  Fair 

Tokay  on  Lenoir,  8  years  old,  gravelly  soil ..Fair  Fair 

Muscat  on  Lenoir,  8  years  old,  dry,  gravelly Weak  Good 

The  vineyard  to  which  these  notes  refer  is  the  same  as  that  in  which 
the  experiment  plot,  reported  on  above,  is  situated.  The  results  cor- 
roborate these  of  the  plot.  The  crops  of  varieties  grafted  on  St.  George 
vary  from  poor  to  fair,  with  the  exception  of  the  Burger,  whose  natural 
tendency  to  heavy  bearing  has  here  been  retained  when  grafted  on 
St.  George. 

J.  H.  Wheeler,  St.  Helena. 

Zinfandel  on  St.  George,  1-8  years  old .-Vigorous  and  satisfactory. 

Zinfandel  on  Lenoir,  1-18  years  old Vigorous  and  satisfactory. 

Zinfandel  on  Riparia -.Poor,  gradually  dying. 

Burger  on  Lenoir,  1-12  years  old --Very  vigorous,  good  crops. 

Muscat  on  Lenoir,  10  years  old --Fair. 

Mr.  Wheeler  states  that  all  varieties  grafted  on  Lenoir  yield  about 
one  half  the  crop  which  they  formerly  did  when  growing  on  their  own 
roots,  but  that  the  crops  are  regular.  The  same  varieties  grafted  on 
St.  George  yield  from  one  half  to  two  thirds  the  crops  formerly  obtained 
before  the  advent  of  Phylloxera.  This  report  is  sufficient  to  condemn 
both  stocks  for  this  vineyard,  as  the  experience  in  Europe  is  that 
whenever  a  stock  suitable  to  the  variety  of  scion  and  the  nature  of 
climate  and  soil  is  used,  the  crop  of  grafted  vines  is  always  larger  than 
that  of  vines  on  their  own  roots.  There  can  be  little  doubt  that  the 
Riparia  X  Rupestris  hybrids  would  give  better  results  in  this  vineyard. 
2— BUL.  197 


130  UNIVERSITY   OP   CALIFORNIA EXPERIMENT   STATION. 

Mr.  Wheeler  states  further  that  Lenoir  gives  late  ripening  and 
low  sugar  with  all  varieties,  that  the  same  varieties  on  St.  George 
ripen  about  two  weeks  earlier  and  attain  from  1%  to  3%  more  sugar. 
These  varieties  on  Riparia  ripen  still  earlier  (1  to  2  weeks)  and  attain 
1%  to  2%  more  sugar  than  on  St.  George.  This  corroborates  the 
experience  on  the  St.  Helena  plot. 

Or  abb's  Black  Burgundy  (Refosco)  and  Petite  Sirah  are  said  to 
fail  occasionally  on  St.  George,  but  a  second  graft  on  the  same  stock 
usually  takes.  This  simply  indicates  a  slight  difficulty  in  grafting, 
and  not  necessarily  any  lack  of  affinity. 

Fred  S.  Ewer,  Rutherford. 

Mr.  Ewer  finds  the  Lenoir  a  very  satisfactory  stock,  as  is  shown 
by  the  following  extract  from  a  letter  which  he  kindly  wrote: 

I  would  like  to  say,  on  the  start,  that  my  knowledge  of  the  different  resistant 
stocks  (except  Lenoir)  is  so  limited  that  I  shall  not  attempt  to  say  much  about  any 
other  than  the  Lenoir. 

I  have  tried  only  three  different  resistants  in  all,  Riparia,  Rupestris  St.  George, 
and  Lenoir,  and  all  grafting  on  same  was  field  work,  as  I  have  never  been  a  believer 
in  bench  work  for  our  place,  believing  we  could  get  a  vineyard  quicker  with  the  field 
grafting,  and  the  little  bench  grafting  I  have  done  has  proved  it  to  my  entire 
satisfaction. 

The  Riparia  was  a  total  failure  with  us  at  Rutherford,  and  a  partial  success  at 
our  small  vineyard  at  St.  Helena.  We  planted  3,000  Rupestris  in  vineyard,  and 
grafted  them  at  one  year  old,  and  only  got  a  stand  of  30%,  where  with  the  Lenoir 
we  nearly  always  got  from  90%  to  95%  of  a  stand,  so  you  can  easily  see  why  I 
favor  the  Lenoir. 

Under  certain  conditions,  such  as  soil,  climate,  moisture,  etc.,  I  am  inclined  to 
think,  from  the  experience  of  others,  that  the  Rupestris  is  better  than  the  Lenoir. 
but  not  for  our  place. 

My  preference  for  the  Lenoir,  summed  up  briefly,  is  as  follows,  viz.  :  Vigorous 
growers,  ease  of  taking  the  graft,  fine  union,  and  few,  if  any,  suckers,  if  properly 
prepared  before  planting. 

I  will  say  that  as  regards  the  bearing  of  the  different  varieties  on  resistant  stock. 
I  believe  we  get  a  better  crop  and  more  sugar  now  than  we  used  to  on  the  vinifera  ; 
that  is  to  say,  on  all  varieties  we  have,  such  as  Chas.  Font,  Golden  Chasselas. 
Semillon,  Sauvignon  vert.  Traminer,  Burger  of  the  white  varieties,  and  Crabb's 
Black  Burgundy,  Alicante  Bouschet,  Petite  Sirah,  Beclan,  and  a  few  Zinfandel 
of  the  reds. 

I  have  Petite  Sirah  grafted  on  Lenoir  fourteen  years  old,  and  growing  strong  and 
vigorous,  and  bearing  good  crops  every  year.  I  wish  you  could  see  the  crop  of 
grapes  on  them  now ;  it  looks  like  eight  tons  to  the  acre. 

I  believe  I  am  the  only  person  in  this  county  who  has  grafted  any  Muscat  on 
Lenoir,  and  my  foreman  said  the  other  day  there  were  more  grapes  on  the  vines 
than  leaves,  showing  that  the  Muscat  will  do  well  on  Lenoir ;  they  are  now  eight 
years  old  and  doing  well. 

It  should  be  noted  that  the  soil  of  Mr.  Ewer's  vineyard  is  very 
deep,  rich,  and  liable  to  become  very  wet  in  the  winter.  These  con- 
ditions are  very  favorable  to  the  growth  of  new  roots,  and,  to 
some  extent,  unfavorable  to  the  Phylloxera.  This  is  shown  by  the  fact 
that  some  Zinfandel  vines,  on  their  own  roots,  are  still  bearing  good 


BULLETIN  197.  GRAPE  CULTURE  IN  CALIFORNIA.  131 

crops,  though  they  have  been  infested  with  Phylloxera  for  ten  years  or 
more.  Under  such  conditions,  the  low  resistance  of  the  Lenoir  is 
sufficient.  It  would  be  unsafe  to  conclude  from  this  that  Lenoir  would 
be  sufficiently  resistant  in  other  soils  and  under  other  conditions. 

The  failure  of  Riparia,  noted  both  by  Mr.  Ewer  and  by  Mr.  Wheeler, 
is  in  part  due  no  doubt  to  the  use  of  unselected  stock.  If  Riparia 
Gloire  had  been  used  it  is  probable  that  very  different  results  would 
have  been  obtained. 

G.  de  Latour,  Rutherford. 

Vigor.  Crop. 

Zinfandel  on  St.  George,  5  years  old,  gravelly  soil Not  good  3  tons 

Burger  on  St.  George,  5  years  old,  gravelly  soil__  Very  good  6  tons 

Alicante  Bouschet  on  St.  George,  5  years  old,  gravelly  soil-Good  4  tons 

Palomino  on  St.  George,  5  years  old,  gravelly  soil Very  good  2  tons 

Sauvignon  vert  on  St.  George,  5  years  old,  gravelly  soil Very  good  2  tons 

Green  Hungarian  on  St.  George,  5  years  old,  gravelly  soil- Very  good  5  tons 

Petite  Sirah  oh  St.  George,  gravelly  soil Weak  Good 

Grand  Noir  on  St.  George,  3  years  old,  gravelly  soil Good  1^  tons 

Mr.  de  Latour  states  further  "*  *  *  it  seems  that  Zinfandel  does 
not  succeed  very  well  on  St.  George;  the  union  with  Petite  Sirah 
seems  defective  also.  The  Riparia  X  Rupestris  3309  seems  to  be  still 
better  than  the  Rupestris  St.  George." 

SONOMA    COUNTY. 

L.  Justi,  Glen  Ellen. 

Reports  that  all  the  varieties  of  wine  grapes  in  his  district  have 
grown  vigorously  and  borne  good  crops  on  Lenoir,  with  the  exception 
of  the  Petite  Sirah,  which  sometimes  fails.  Alicante  Bouschet  and 
Burger  do  particularly  well. 

K.  Nagasawa,  Santa  Rosa. 

Zinfandel  on  St.  George,  5  years  old,  on  light  ashy  soil,  becoming 
very  hard  in  summer,  are  very  vigorous  and  yield  very  well.  Alicante 
Bouschet,  Beclan  and  Muscadelle  du  Bordelais  on  the  same  stock  are 
doing  well,  though  too  young  to  bear  yet. 

SAN   JOAQUIN   COUNTY. 

F.  and  F.  A.  Arnold,  Stockton. 

Nature  of  soil:  24  acres — 3  parts  adobe  and  1  part  river  sand  and 
slackens ;  3  to  6  feet  deep  ;  no  overflow  for  years ;  no  irrigation.  Plowed 
12  inches  deep  before  planting  cuttings;  field  grafting.  Burger  and 
Mission  doing  well  on  Rupestris  St.  George,  Riparia  Gloire,  Riparia 
Grande  Glabre,  and  Riparia  X  Rupestris  hybrids. 


132  UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 

SANTA    CLARA    COUNTY. 

Paul  Masson,  San  Jose. 

Zinfandel  on  Rupestris  St.  George,  6  years  old,  satisfactory,  good 
unions,  healthy  looking,  but  do  not  bear  abundantly. 

Burger  on  Rupestris  St.  George,  4  to  7  years  old,  field  grafted;  bad. 
Poor  success  from  beginning,  many  dying  every  year,  apparently 
from  poor  unions  and  lack  of  affinity.  Same  results  on  sandy,  deep, 
rich  gravelly  and  rich  loamy  soils. 

Carignane  and  Pinot,  11  years  old,  planted  on  special  soil,  are 
doing  well. 

"I  have  quite  a  few  acres  of  11-year-old  vines  grafted  on  Rupestris 
St.  George,  including  the  following  varieties:  Carignane  Mondeuse, 
Alicante.  Bouschet,  Aramon,  Grand  Noir,  Durif,  Grenache,  Pinot, 
Semillon,  Sauvignon  vert,  Folle  blanche,  Colombar,  Pinot  blanc.  These 
are  all  doing  very  well,  and,  if  anything,  more  vigorous  and  prolific 
than  ungrafted  vines  of  the  same  age.  Carignane  and  Grenache,  12 
years  old  on  St.  George,  have  never  failed  to  give  a  large  crop,  and 
Aramon  also  seems  very  prolific. ' ' 

Mataro  (grafted)  is  not  very  satisfactory;  it  bears  heavily,  but 
many  die  during  the  hot  summer. 

Thos.  Casalegno,  Evergreen. 

Zinfandel  on   St.   George,   vigorous ;   coulures. 

Mondeuse  on  Riparia,  fair  vigor  and  crop. 

St.  Macaire  on  Riparia,  9  years  old,  rocky  soil,  light  growth,  fair  crop. 

Carignane  on  Riparia,  10  years  old,  good  growth  and  crop. 

Carignane  on  St.  George,  10  years  old,  clay  soil,  good  growth  and  crop. 

Carignane  on  St.  George,  10  years  old,  gravel  soil,  good  growth,  but 
coulures. 

Mataro  on  St.  George,  7  years  old,  coulures. 

Mataro  on  Riparia,  good  growth  and  crop. 

Alicante  Bouschet  on  St.  George,  5  years  old,  strong  growth,  coulures. 

Palomino  on  St.  George,  7  years  old,  clay  loam,  good  growth  and  crop. 

Chasselas  on  St.  George,  7  years  old,  clay  loam,  good  growth  and  crop. 

ALAMEDA   COUNTY. 

Grau  &  Werner,  Irvington. 

Tannat  on  Lenoir,  13  years  old,  healthy  growth,  but  very  light  crop. 

SANTA  CRUZ  COUNTY. 

E.  E.  Meyer,  Wrights. 

Valdepenas,  7  years  old,  and  Green  Hungarian,  6  years  old,  grafted 
on  St.  George,  are  growing  vigorously,  but  the  crops  are  not  altogether 
satisfactory. 


BULLETIN  197. 


GRAPE    CULTURE    IN    CALIFORNIA. 


133 


Summary  of  Reports  from  Growers. 


VARIETY. 

Vigor. 

Crop. 

Zinfandel  on  St.  George 

Good  5 

Poor  1 

Good  1 

Fair  4 

Zinfandel  on  Riparia 

Poor  1 

Zinfandel  on  Lenoir  _ 

Good  2 

Fair  2 

Carignane  on  St.  George 

Good  3 

Good  2 

Fair  1 

Carignarie  on  Riparia 

Good  2 

Good  2 

Carignane  on  Lenoir 

Good  1 

Good  1 

Alicante  Bouschet  on  St.  George 

Good  3 

Good  1 

Fair   1 

Alicante  Bouschet  on  Lenoir 

Good  1 

Good  1 

Petite  Sirah  on  St.  George 

Good  1 

Poor  1 

Good  2 

Petite  Sirah  on  Lenoir 

Good  1 

Poor  2 

Good  1 

Fair  1 

Mondeuse  on  St.  George 

Good  1 

Good  1 

Mondeuse  on  Riparia 

Fair  1 

Fair  1 

St.  Macaire  on  St.  George 

Good  1 

Good  1 

St.  Macaire  on  Riparia 

Fair  1 

Fair   1 

Valdepenas  on  St.  George           

Good  1 

Fair  1 

Durif  on  St.  George 

Good  1 

Good  1 

Mataro  on  St.  George 

Poor  1 

Good  1 

Fair  1 

Mataro  on  Riparia 

Good  1 

Good  1 

Burger  on  St.  George 

Good  2 

Poor  1 

Good  2 

Burger  on  Lenoir 

Good  2 

Good  2 

Palomino  on  St.  George 

Good  2 

Good  2 

Poor  1 

Palomino  on  Lenoir            _ 

Good  2 

Good  2 

Johannisberg  Riesl.  on  St.  George 

Good  1 

Poor  1 

Johannisberg  Riesl.  on  Riparia 

Good  1 

Fair  1 

Semillon  on  St.  George 

Good  1 

Good  1 

Semillon  on  Lenoir 

Good  1 

Good  1 

Colombar  on  St.  George 

Good  3 

Good  1 

Fair  1 

Poor  1 

Colombar  on  Riparia 

Good  1 

Good  1 

Colombar  on  Lenoir 

Good  1 

Good  1 

Green  Hungarian  on  St.  George 

Good  1 

Fair   1 

Grenache  on  St  George 

Good  2 

Good  1 

STOCKS  FOR  THE  FRESNO  REGION. 

In  1903  five  plots  of  resistant  vines  were  planted  in  the  neighborhood 
of  Fresno  on  land  kindly  placed  at  our  disposal  for  that  purpose  by 
various  growers. 

The  great  importance  of  the  raisin  and  wine  industries  in  the  upper 
San  Joaquin  Valley,  and  the  special  climatic  and  soil  conditions  of 
that  region,  make  it  very  necessary  that  we  should,  as  soon  as  possible, 
obtain  some  reliable  information  regarding  stocks  that  will  succeed 
there.  European  experience  can  be  relied  on  less  in  this  region  than 
in  the  coast  valleys.  No  part  of  France  resembles  the  San  Joaquin 
Valley,  and  in  the  parts  of  Spain  which  show  the  most  nearly  similar 
conditions  the  problems  of  resistant  stocks  are  hardly  more  advanced 
than  in  California. 

The  five  plots  were  planted  primarily  to  determine  the  vigor  of  the 
most  promising  stocks  in  the  region,  and  to  provide  cuttings  for  dis- 
tribution to  enable  growers  to  make  tests  on  their  own  places. 

The  following  varieties,  which  include  nearly  all  those  which  have 
given  the  best  results  in  Europe,  were  planted  : 

Pure  American   Varieties. 

1.  Riparia   Gloire  de   Montpellier. 

2.  Riparia  Grande  Glabre. 

3.  Rupestris   Martin. 

4.  Rupestris   St.   George. 

5.  Berlandieri  Ress6guier    No.  1. 


134  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

America- American  Varieties. 

G.  Riparia  X  Rupestris  3306. 

7.  Riparia  X  Rupestris  3309. 

8.  Riparia  X  Rupestris  10114. 

9.  Riparia  X  Berlandieri  33E. 

10.  Riparia  X  Berlandieri  34B. 

11.  Riparia  X  Berlandieri  15711. 

12.  Riparia  X  Berlandieri  420A. 

13.  Rupestris  X  Berlandieri  219A. 

14.  Rupestris  X  Berlandieri  301. 

15.  Solonis  X  Riparia  1615. 

16.  Solonis  X  Riparia  1616. 

,  17.  Riparia  X  Cordifolia-Rupestris  1068. 

18.  Solonis  X  Cordifolia-Rupestris  2024. 

Franco-American   Varieties. 

19.  Mataro  X  Rupestris  1202. 

20.  Aramon  X  Rupestris  No.  1. 

As  might  have  been  expected,  nearly  all  of  these  varieties  which 
started  grew  vigorously  in  the  rich  soil  of  the  region.  Cuttings  were 
used  in  making  the  plantations,  and  the  plots  show  strikingly  the 
differences  in  facility  of  rooting  of  the  different  stocks.  The  Berlandieri 
and  Berlandieri  crosses  rooted  badly.  The  best  of  the  latter  in  this 
respect  was  the  Riparia  X  Berlandieri  15711. 

The  four  most  vigorous  of  the  stocks  were  1616,  1202,  3306  and  St. 
George.  All  of  these  in  all  the  plots  grew  with  extraordinary  vigor 
and  rapidity. 

Seven  other  varieties  grew  with  scarcely  less  vigor.  These  were 
3309,  10114,  1615,  Riparia  Gloire,  15711,  Aramon  X  Rupestris  No.  1,  and 
1068.  Four  varieties,  33E,  34E,  2024,  and  Rupestris  Martin  grew  with 
fair  vigor,  but  were  distinctly  inferior  to  the  above. 

The  only  varieties  of  the  list  which  made  poor  growth  were  Riparia 
Grande  Glabre,  219A  and  301. 

Stocks  for  Muscat. — The  importance  of  the  Muscat  of  Alexandria, 
as  the  basis  of  our  raisin  vineyards,  makes  it  highly  important  that 
a  suitable  stock  for  this  variety  should  be  found  as  soon  as  possible. 

The  invasion  of  the  raisin  vineyards  of  Spain  by  Phylloxera  is  com- 
paratively recent,  and  little  information  is  obtainable  regarding  the 
use  of  resistant  stock  there.  In  a  general  way  it  is  stated  that  the 
usual  resistant  stocks  are  being  used  in  the  principal  raisin-growing 
regions  of  the  Peninsula  with  success.  The  Muscat  of  Alexandria  is 
being  grown  to  a  limited  extent  as  a  table  grape  in  southern  France, 
and  is  said  to  succeed  on  any  vigorous  stock. 

On  the  other  hand,  in  South  Africa,  Muscat  vineyards  grafted  on 
Rupestris  St.  George,  Riparia  Gloire,  Aramon  X  Rupestris  No.  1,  and 
Rupestris  Metallica  have  almost  uniformly  failed.  After  bearing 
several  good  crops  the  vines  have  generally  died.  No  satisfactory 


BULLETIN   197.  GRAPE    CULTURE    IN    CALIFORNIA.  135 

explanation  of  this  difference  has  been  advanced.  The -most  plausible 
seems  to  be  that  the  vines  have  been  killed  by  overbearing.  The  vines, 
in  fact,  have  borne  large  crops  before  dying,  and  the  only  stock  on 
which  they  have  remained  healthy  is  Lenoir,  which  has  a  tendency  to 
induce  light  bearing  with  most  varieties. 

The  grafting  of  Muscats  on  resistant  stocks  has  been  little  practiced 
in  California,  but  a  few  growers  have  vines  which  have  been  bending 
several  years  on  various  stocks. 

One  grower  reports  that  Muscats  on  Lenoir,  10  years  old,  have  given 
fair  results;  another  that  they  are  weak,  but  bear  well.  One  grower 
in  Tulare  County  has  dug  up  his  Muscat  .vineyard  grafted  on  Lenoir 
because  so  many  of  the  vines  had  died.  Two  growers  report  that  they 
have  Muscats  grafted  on  St.  George  which  have  been  bearing  well  and 
growing  vigorously  for  from  3  to  6  years.  Another  grower  reports 
that  his  Muscats  grafted  on  St.  George  and  on  Riparia  Gloire  have 
given  three  good  crops  and  are  equally  vigorous.  These  results  are  on 
the  whole  encouraging. 

While  the  question  of  the  selection  of  the  best  stock  is  not  so  pressing 
in  the  case  of  raisin  grapes  as  in  that  of  wine  grapes,  because  the 
greater  part  of  the  raisin  district  is  still  uninfested  by  Phylloxera,  it 
will  sooner  or  later  be  of  vital  importance  to  the  industry.  For  this 
reason  a  number  of  test  plots  have  been  started,  with  the  cooperation 
of  growers  in  various  sections  where  raisins  are  produced. 

In  1904  Muscat  cuttings  were  bench  grafted  on  the  following  re- 
sistant stocks : 

Rupestris  St.  George. 
Riparia  Gloire  de  Montpellier. 
Riparia  X  Rupestris  3309,  3306,  101". 
Solonis  X  Riparia  1616. 
Riparia  X  Berlandieri  33E,  34E,  157". 
Rupestris  X  Berlandieri  301A. 
Solonis  X  Cordifolia-Rupestris  2024. 
Aramon  X  Rupestris  No.  1. 
Mourvedre  X  Rupestris  1202. 
Lenoir. 

Several  hundred  rooted  bench  grafts  on  St.  George  and  1202  were 
obtained  and  distributed  to  a  number  of  growers  in  various  districts, 
principally  in  Fresno  County.  Smaller  quantities  on  the  other  stocks 
were  obtained  and  distributed  to  a  more  limited  number  of  growers. 

Notes  taken  on  the  quality  of  the  bench  grafts  before  they  were 
distributed  were  as  follows: 

Muscat  on  St.  George.     Heavy  growth,  complete  unions  but  large  swellings. 
Muscat  on  101*.     Good  growth,  complete  unions,  large  swellings. 
Muscat  on  3306.     Small  growth,  complete  unions,  small  swellings. 
Muscat  on  1202.     Heavy  growth,  complete  unions,  large  swellings. 
Muscat  on  Lenoir.     Good  growth,  complete  unions,  small  swellings. 


136  UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 

Reports  have  been  received  from  most  of  the  growers  who  received 
vines,  but  they  are  of  little  value  yet  as  showing  relative  vigor  of  the 
various  stocks.  One  of  the  most  complete  reports  is  given  below,  by 
Dr.  W.  N.  Sherman,  Fresno: 

Muscat  on  St.  George.     All  grew  vigorously. 

Muscat  on  Riparia  Gloire.     All  grew  vigorously. 

Muscat  on  10114.    Four  out  of  six  lived  and  made  fair  growth. 

Muscat  on  3300.     Six  out  of  ten  lived  and  grew  vigorously. 

Muscat  on  3309.     All  lived  and  grew  vigorously. 

Muscat  on  1616.     Six  out  of  seven  lived  and  grew  vigorously. 

Muscat  on  33E.     All  lived,  but  made  poor  growth. 

Muscat  on  2024.  Four  out  of  six  lived  and  made  fair  growth. 

Muscat  on  1202.     All  lived  and  made  vigorous  growth. 

Muscat  on  Lenoir.     Nine  out  of  ten  lived  and  made  fair  growth. 

These  vines  were  planted  in  overwet  soil,  and  were  all  more  or  less 
injured  by  early  autumn  frost.  Too  much  emphasis  should  not,  there- 
fore, be  placed  on  the  fact  that  some  of  them  died. 

The  other  reports  show  in  general  that  the  Muscats  on  St.  George 
3306  and  Riparia  Gloire  on  the  whole  made  the  best  growth,  while 
10114  and  33E  generally  made  poor  growth.  The  other  stocks  gave 
intermediate  results.  The  results  the  first  year  are,  however,  apt  to  be 
misleading,  even  as  regards  vigor,  for  some  stocks,  for  example. 
Berlandieri  and  its  hybrids,  are  slow  starting,  but  make  a  vigorous 
growth  later.  The  question  of  crop  can  be  determined  of  course  only 
after  several  years  of  trial. 


GENERAL   RECOMMENDATION. 

Only  the  pressing  necessity  of  some  rules  to  guide  us  in  our  imme- 
diate plantations  will  excuse  the  making  of  recommendations  as  to 
stocks  in  the  present  incomplete  state  of  our  knowledge  of  the  behavior 
cf  the  various  stocks  in  the  diverse  conditions  of  our  grape-growing 
regions.  The  present  tendency  to  plant  St.  George  in  all  soils  and  in  all 
localities,  however,  is  undoubtedly  wrong,  and  has  led  to  disappoint- 
ment in  many  cases,  and  wre  already  possess  sufficient  data  to  enable 
us  to  choose  something  better  for  many  locations. 

The  Rupestris  St.  George  has  given  its  best  results  in  the  hot,  dry 
interior  on  deep  soils.  It  seems  to  be  a  particularly  good  stock  for 
Tokay  and  Alicante  Bouschet  under  such  conditions.  Its  great  vigor 
seems  to  promise  a  diminution  of  the  tendency  of  the  Tokay  to  sunburn, 
and  the  coulure  which  it  produces  with  many  varieties  only  extends 
to  the  production  of  loose  bunches  with  the  Tokay.  This  looseness  of 
bunch  is  a  distinct  advantage  with  this  variety.  The  coloring  and 
ripening  of  the  Tokay  leave  nothing  to  be  desired  when  grafted  on 
St.  George. 


BULLETIN  197.  GRAPE    CULTURE    IN    CALIFORNIA.  137 

For  a  great  majority  of  our  soils  and  varieties  the  two  Riparia  X 
Rupestris  hybrids  3306  and  3309  promise  to  be  superior  in  every  way 
to  the  St.  George.  The  former  for  the  moister  soils  and  the  latter  for 
the  drier.  The  vigor  and  bearing  of  all  varieties  tested  on  these  two 
stocks  has  so  far  been  excellent,  and  they  should  in  most  cases  replace 
St.  George  in  all  but  the  hottest  and  driest  deep  soils. 

For  the  wettest  locations  in  which  vines  are  planted — in  places  where 
the  water  stands  for  many  weeks  during  the  winter,  or  where  the 
bottom  water  rises  too  near  the  surface  during  the  summer — the  most 
promising  stock  is  Solonis  X  Riparia  1616. 

For  moist,  rich,  deep,  well-drained  soils,  especially  in  the  coast 
counties  and  on  northerly  slopes,  the  St.  George  is  utterly  unsuited. 
The  crops  on  this  stock,  in  such  locations,  are  apt  to  be  small,  and 
the  sugar  contents  of  the  grapes  defective.  In  these  locations  the 
Riparia  Gloire  is  much  to  be  preferred,  and  will  undoubtedly  give 
larger  crops  of  better  ripened  grapes. 

None  of  the  above  stocks  give  good  results,  as  a  rule,  in  very  compact 
soils.  For  such  soils  the  most  promising  varieties  are  1068  in  the  drier, 
and  Aramon  X  Rupestris  No.  1  or  2024  in  the  wetter  locations.  In 
dry,  shallow  soils  420A  and  15711  give  promise  of  being  excellent  stocks. 

This  covers  most  of  the  soil  conditions  which  occur  in  California. 
The  only  other  cases  which  demand  consideration  are  the  varieties  with 
defective  affinity.  For  these  varieties  the  most  promising  stock  is  1202. 
This  stock  makes  excellent  unions  with  many  varieties  which  fail  on 
most  resistants,  and  is  to  be  tentatively  recommended  for  Emperor, 
Ferrara,  Cornichon,  Muscat,  Mataro,  Folle  blanche,  Pinot,  Gamay. 
Gutedel  and  any  varieties  which  have  not  given  generally  satisfactory 
results  on  Riparia  and  Rupestris. 

These  recommendations  may  be  summarized  as  follows: 

For  average,  good  soils  in  most  locations — 

1.  Drier  soils 3300 

2.  Moister  soils    3306 

For  special  soils — 

3.  Dry,  deep,  in  hot  regions  and  locations St.  George 

4.  Dry,  deep,  in  cooler  regions  and  locations .Rup.  Martin 

5.  Dry,  shallow   . . 420A  or  157" 

6.  Dry  and  very  compact 10G8 

7.  Wet  and  very  compact Aramon  X  Rup.  No.  1  or  2024 

8.  Wet,   loose    1616 

9.  Rich,  moist,  deep,  well  drained  in  the  cooler  localities. .  .Rip.  Gloire 
For  varieties  of  defective  affinity  in  good  soils 1202 


138 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


DESCRIPTION   OF  THE  PRINCIPAL  RESISTANT  STOCKS. 

In  order  to  enable  the  grower  to  determine  the  correctness  of  the 
labeling  of  his  resistant  vines,  the  following  brief  description,  adapted 
for  the  most  part  from  "Les  Vignes  Americaines"  of  Prof.  L.  Ravax 
and  accompanied  by  reproductions  of  original  photographs,  will  be 
of  assistance: 


FIG.  1.    Riparia  Gloire  de  Montpellier.    One  third  natural  size. 

Riparia  Gloire  de  Montpellier  (Fig.  1). — The  most  vigorous  of  all 
varieties  of  Riparia.  Leaves  very  large,  as  wide  as  long;  young  leaves 
and  tips  pale  green,  canes  and  trunk  thick.  Male  vine. 


BULLETIN  197.  GRAPE    CULTURE    IN    CALIFORNIA.  139 

Roots  well  and  grafts  easily,  either  as  cuttings  or  in  the  field.  Trunk 
grows  almost  as  large  as  the  scion.  Vines  on  this  stock  bear  well,  and 
the  grapes  are  large,  sweet  and  early. 

Riparia  Grande  Glabre  (Fig.  2). — Very  vigorous,  but  does  not  grow 
so  stout  as  the  Riparia  Gloire.  Leaves  large,  longer  than  wide,  with  an 


FIG.  2.    Riparia  Grande  Glabre.    One  half  natural  size. 

almost   rectangular  outline,  due  to  the  short   terminal  lobe  and  the 
straight  sides.    Roots  thin,  hard  and  wiry.    Fertile  vine. 

Roots  well,  but  does  not  take  the  graft  so  well  as  Riparia  Gloire. 
Almost  equal  to  Riparia  Gloire,  but  subject  to  ' '  f olletage. "  Folletage, 
or  sudden  dying  of  the  vine,  is  a  common  fault  of  the  unselected 
Riparias  formerly  grown  in  California,  and  for  this  and  other  reasons 


140 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


FIG.  3.    Rupestris  Martin.     One  half  natural  size. 


the  Riparia  Gloire  is  to  be 
preferred  to  the  present  or 
other  varieties  of  this  species. 

Rupestris  Martin  (Fig.  3). 
—Very  vigorous  and  one  of 
the  most  robust  of  the  exist- 
ing stocks.  Leaves  larger 
than  those  of  Rupestris  St. 
George,  and  with  a  V-shaped 
petiolar  sinus.  Canes 
glabrous,  pinkish,  long  and 
thick. 

Roots  easily,  but  is  more 
difficult  to  graft  than  St. 
George.  The  grafts  which  grow  are  very  satisfactory  and  are  less 
liable  to  coulure  than  grafts  on  St.  George.  It  succeeds  in  drier  situa- 
tions than  the  latter. 
Male  vine. 

Rupestris  St. 
George  (Fig.  4).— 
Perhaps  the  most 
vigorous  of  all  the 
stocks  grown  when 
planted  in  suitable 
locations.  Leaves 
small ;  the  petiolar 
sinus  very  open, 
with  a  j  -shaped  out- 
line. Canes  and 
trunk  very  thick 
and  robust. 

This  variety  roots 
and  grafts  with 
great  facility,  and 
grows  at  least  as 
large  as  any  scion 
which  is  grafted  on 
it.  Succeeds  in  any 
soil  except  those  un- 
derlaid with  an  im- 
permeable or  stiff 
clay  subsoil. 

FIG.  4.    Rupestris  St.  George.    One  half  natural  size. 


BULLETIN  197. 


GRAPE    CULTURE    IN    CALIFORNIA. 


141 


FIG.  4£.    Rupestris  Metallica  of  South  Africa. 


Rupestris    Metallica    (Fig. 
. — The  best  varieties   of 

Riparia    and    Rupestris    give 

excellent    results    when    they 

grow  under  appropriate  soil 

and      climatic      conditions. 

Their    range    of    adaptation, 

however,      is      comparatively 

small — that  is,  they  are  likely 

to  .give  unsatisfactory  results 

when     planted     in     locations 

which  differ  in  any  consider- 
able degree  from  those  which 

suit  them  best.     This   seems 

to  be  due  in  great  part  to  the 

direction  their  roots  naturally 

take.     Roots  of  Riparia   are 

for  the  most  part  spreading 

and  superficial,  and  succeed  only  where  sufficient  moisture  exists  near 

the  surface.     Roots  of  Rupestris  are,  on  the  contrary,  plunging  and 

deeply  penetrating,  and  fail  if  an  impenetrable  subsoil  prevents  their 

taking  their  natural  posi- 
tion. 

Experience  has  shown 
that  crosses  between 
Riparia  and  Rupestris 
have  a  much  wider  range 
of  adaptation  than  either 
of  their  parents,  owing 
to  the  fact  that  they  are 
capable  of  forming  a 
strong  root  system  in 
both  the  upper  and  lower 
layers  of  the  soil.  More- 
over, the  best  of  them 
retain  all  the  good  quali- 
ties of  both  parents — 
high  resistance  to  Phyl- 
loxera, ease  of  rooting 
and  grafting,  vigor  and 
fruitfulness  of  grafts. 
The  best  of  these  hybrids, 
according  to  European 


FIG.  5.    Riparia  x  Rupestris  3309.    One  half  natural  size. 


142 


UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 


experience,  are  those  known  by  the  numbers  3309,  3306  and  10114.    The 
first  two  are  the  most  promising  in  California. 

Riparia  X  Rupestris  3309  (Fig.  5).— This  variety  resembles  in  habit 
a  Rupestris,  and  the  leaves  are  intermediate  between  those  of  the  two 
parents. 

It  has  small  leaves,  which,  on  the  laterals,  are  rounded  and  without 
lobes.  The  young  shoots  and  leaves  are  sparingly  pubescent,  but  the 
rest  of  the  vine  is  glabrous,  and  by  this  character  readily  distinguished 

from  3306.  The  vine  is 
male,  and  therefore  does 
not  produce  fruit. 

Riparia  X  Rupestris 
3306  (Fig.  6).  — The 
general  habit  of  this 
variety  resembles  also 
that  of  a  Rupestris, 
but  it  is  easily  distin- 
guished from  3309  by  its 
strongly  pubescent  leaves 
and  canes.  Male  vine. 

Riparia  X  Rupestris 
101^  (Fig.  7).  — This 
variety  resembles  in 
habit  its  Riparia  parent 
more  than  3309  or  3306. 
Its  range  of  adaptation 
is  less  than  that  of  the 
latter,  and  it  is  most 
suited  to  fairly  rich 

soils,  such  as  those  suitable  to  Riparia.    It  bears  small  bunches  of  small, 

round,  black  grapes. 

Berlandieri  Resseguier  No.  1  (Fig.  8). — The  pure  Berlandieri  varie- 
ties have  all  the  qualities  required  in  a  stock — resistance  to  Phylloxera, 
ease  of  grafting,  permanency  of  union,  fertility  of  the  scion,  adaptation 
to  varied  soils — except  one,  that  of  ease  of  rooting.  From  100  cuttings 
only  10  to  15  rooted  vines  are  obtained  by  the  usual  methods  of  propa- 
gation. For  this  reason  this  species  has  never  been  used  to  any  great 
extent.  Certain  crosses  of  this  species  with  Riparia,  however,  while 
retaining  the  merits  of  the  Berlandieri,  possess  rooting  qualities  almost 
equal  to  Riparia.  They  are  particularly  promising  for  shallow,  stiff 
soils  where  the  Riparia  X  Rupestris  hybrids  might  suffer. 


FIG.  6.     Riparia  x  Rupestris  3306.    One  half  natural  size. 


BTTLLETIN  197. 


GRAPE    CULTURE    IN    CALIFORNIA. 


143 


Riparia  X  Berlandieri  15711  (Fig.  9). — This  variety  was  obtained 
by  crossing  a  Berlandieri  with  pollen  from  Riparia  Gloire  de'Mont- 
pellier.  It  has  the  habit  and  leaves  of  a  Berlandieri,  and  a  root  system 
intermediate  between  those  of  its  parents.  It  is  thoroughly  resistant 
to  Phylloxera,  and  its  grafts  are  vigorous,  fruitful,  ripen  well,  and  are 
not  subject  to  coulure.  The  cuttings  root  fairly  well,  and  field  grafts 
succeed  very  well.  It  produces  an  abundance  of  strong  canes,  but 


FIG.  7.    Riparia  x  Rupestris  10114.    One  half  natural  size. 

these  do  not  ripen  well  in  the  cooler  localities.     It  produces  medium- 
sized  bunches  of  round,  black,  pulpy  grapes. 

Riparia  X  Berlandieri  420 A  (Fig.  10). — This  variety  is  perhaps 
superior  to  15711.  The  cuttings  root  more  easily,  graft  as  well,  and 
mature  more  regularly.  It  is  more  suited  to  bench  grafting  than  the 
former,  and  makes  vigorous  and  fruitful  grafted  vines.  Male  vine. 

The  Solonis  is  a  hybrid  of  unknown  parentage  which  resembles  in 


144  UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 

its  habits  a  Eiparia.  It  was  at  one  time  much  used  as  a  stock,  but 
its  resistance  to  Phylloxera  is  insufficient.  In  California  vines  grafted 
on  Solonis  have  been  so  weakened  by  Phylloxera  as  to  be  useless.  Its 
only  use  is  for  wet,  sandy  soils,  where  it  gives  good  results. 

The  good  qualities  of  Solonis  are  found  in  certain  of  its  crosses  with 
Riparia,  of  which  the  most  promising  for  California  is  1616. 


FIG.  8.    Berlandieri  Resse'guier  No.  1.    One  half  natural  size. 

Solonis  X  Riparia  1616  (Fig.  11). — This  variety  is  very  vigorous, 
and  the  cuttings  root  and  graft  well.  It  is  sufficiently  resistant  to 
Phylloxera,  and  is  to  be  recommended  for  sandy  and  especially  wet 
soils.  Vine  fertile,  producing  small,  round,  black  grapes. 

Eiparia  X  Rupestris-Cordifolia  1068  -(Fig.  12). — This  variety  is 
vigorous  and  thoroughly  resistant  to  Phylloxera.  It  is  particularly 
recommended  for  stiff  clay  soils  which  become  hard  after  rain  and 
easily  dry  out.  It  is  in  just  such  soils  that  Rupestris  St.  George  and 


BULLETIN  197. 


GRAPE    CULTURE    IN    CALIFORNIA. 


145 


Kiparia  have  often  failed  in  California,   and  this  variety  therefore 
promises  to  be  useful.    Vines  produce  small,  round,  black  grapes. 

Solonis  X  Cordifolia-Rupestris   202*    (Fig.    12%). — This   variety   is 
adapted  to  soils  similar  to  those  suited  to  1068,  but  resists  humidity 


FIG.  9.    Riparia  x  Berlandieri  157H.    One  half  natural  size. 

better.  Prosper  Gervais  in  his  report  to  the  Congres  International 
de  Viticulture  of  1900,  at  Paris,  says:  "The  varieties  2024  and  1068 
are  especially  suited  to  non-calcareous  clay  soils;  the  latter  succeed 
in  dry.  poor,  hot  soils,  providing  they  are  not  too  shallow;  the  former 
in  soils  which  are  both  compact  and  wet." 

Aramon  X  Rupestris  No.  1  (Fig.  13). — This  variety  is  the  result  of 
a  cross  between  the  vinifera  variety  Aramon  and  Rupestris  Ganzin. 
3— BUL.  197 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


FIG.  10.    Riparia  x  Berlandieri  420A. 
One  half  natural  size. 


(Mataro)  and  a 
Rupestris.  It  is, 
perhaps,  the  most 
widely  planted  of 
all  the  American 
vinifera  hybrids. 
Prosper  Gervais 
describes  it  as  "  A 
stock  character- 
ized by  its  ex- 
treme vigor,  rapid 
development,  ease 
of  rooting  and 
grafting,  and  the 
f ruitfulness  of  its 
grafts."  It  is  par- 
ticularly suited 
to  deep,  rich, 
humid,  clay  soils, 
and  makes  excel- 
lent unions  with 
all  varieties  of 
vinifera. 

The  vine  is 
fruitful,  bearing 
large  numbers  of 
small,  round, 
bluish-black 


The  leaves  resemble  Rupestris, 
and  unlike  most  crosses  contain- 
ing vinifera,  its  resistance  to 
Phylloxera  is  quite  sufficient  and 
superior  to  that  of  Lenoir.  It  is 
very  vigorous  and  roots  easily 
from  cuttings.  It  is  somewhat 
difficult  to  graft,  but  when  suc- 
cessful the  grafts  make  good 
unions  and  are  vigorous  and 
fruitful.  Its  chief  merit  is  that 
it  succeeds  in  wet,  compact  soils, 
where  most  other  varieties  fail. 

Mourvedre  X  Rupestris  1202 
(Fig.  14). — This  variety  is  a 
cross  between  the  Mourvedre 


FIG.  11.    Solonis  x  Riparia  1616.    One  half  natural  size. 


BULLETIN  197.  GRAPE   CULTURE   IN   CALIFORNIA.  147 

grapes.  It  is  grown  extensively  in  France,  Spain,  Sicily,  Portugal, 
and  Roumania,  and  has  given  good  results  wherever  tried.  In  Cali- 
fornia its  vigor  is  remarkable,  exceeding  even  that  of  Rupestris 
St.  George. 

OTHER  VINE  DISEASES. 

Oidium. — The  cause  and  treatment  of  this  disease  have  been  dis- 
cussed  in   Bulletin   186,    and   the   recommendations   in   it   have   been 


FJG.  12.    Riparia  x  Rupestris-Cordifolia  1068.    One  half  natural  size. 

followed  by  a  large  number  of  growers  this  year  in  all  parts  of  the 
State,  usually  with  success. 

All  of  the  reported  failures  which  have  been  investigated  have  been 
due  either  to  the  incomplete  carrying  out  of  the  recommendations,  or  to 
the  fact  that  the  vines 'were  suffering  from  some  other  cause  which 
had  been  mistaken  for  Oidium. 


148 


UNIVERSITY  OF   CALIFORNIA — EXPERIMENT   STATION. 


FIG   12i.     Solonis  x  Cordifolia  Rnpi-stris  2024. 

for  its  effect  on  the  setting  of 
Sulfuring  later,  if  needed,  is  a 
well  done.     This  is 
true  for  the  whole 
of  the  two  central 
valleys      and      for 
most  of  California, 
except     the     coast 
belt  subject  to  sum- 
mer ocean  fog. 


Definition  of  a 
Thorough  and 
Effective  First  Sul- 
furing.— The  first 
sulfur  ing  should  be 
made  when  the 
shoots  are  between 
6  and  15  inches 
long.  It  should  be 
done  in  such  a  way 
that  every  part  of 
every  leaf  of  every 
vine  in  all  parts  of 
the  vineyard  re- 
ceives some  sulfur, 
and  the  whole  vine- 


The  most  common  mistake 
of  those  who  have  attempted 
to  follow  the  directions  of  the 
bulletin  has  been  a  failure  to 
treat  the  vines  thoroughly  or 
rapidly  enough  in  the  begin- 
ning of  the  season.  It  can 
not  be  too  strongly  urged  that 
the  most  effective  way  to  con- 
trol the  mildew  is  by  a  thor- 
ough and  effective  sulfuring 
in  the  beginning  of  the  season. 
This  alone  will  in  most  parts 
of  the  State  keep  the  vines 
free,  and  the  sulfuring  during 
the  blossoming  is  needed  only 

the  fruit,  and  as  an  extra  precaution. 

proof  that  the  first  two  have  not  been 


FIG.  13.     Aramon  x  Rupestris  No.  1.    One  half  natural  size. 


BULLETIN  197. 


GRAPE    CULTURE    IN    CALIFORNIA. 


149 


yard  should  be  gone  over  in  as  short  a  time  as  possible.  This  will 
be  a  thorough  sulfuring.  To  be  effective,  it  must  be  followed  imme- 
diately by  two  or  three  days  of  warm  weather.  Unless  this  happens, 
the  sulfuring  should  be  repeated  as  many  times  as  are  necessary  until 
the  proper  weather  conditions  are  obtained. 


FIG.  14.    Mourvedre  x  Rupestris  1202.    One  half  natural  size. 

Mysterious  Dying  of  Vines  ("Anaheim  Disease"}. — The  vine,  like 
most  plants,  especially  fruit  trees,  which  are  cultivated  on  a  large  scale, 
is  subject  to  diseases  of  more  or  less  intensity  whose  cause  is  not 
thoroughly  understood.  These  diseases  are  (1)  caused  by  parasitic 
organisms  which  have  so  far  escaped  detection,  or  (2)  what  is  usually 
known  as  ''physiological." 

Physiological  diseases  are  presumably  due  to  some  unfavorable  con- 
ditions. For  example,  chlorosis,  cr  the  failure  of  the  leaves  to  develop 


150  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

chlorophyll  properly,  is  due  to  an  excess  of  soluble  lime  carbonate  in 
the  soil,  and  is  intensified  by  cold,  dampness  and  the  susceptibility  of 
the  variety. 

The  most  serious  of  these  two  classes  of  diseases,  which  affects  the 
vines,  is  the  Anaheim,  or,  as  it  is  sometimes  called,  the  California  Vine 
Disease.  Notwithstanding  that  it  has  been  the  subject  of  continuous 
investigation  for  over  fifteen  years  its  cause  is  still  quite  obscure.  Even 
the  characterization  and  detection  of  the  disease  are  so  uncertain  that 
vineyards,  which  after  several  years  of  observation  by  the  most  ex- 
perienced investigators  have  been  pronounced  infected,  have  later  been 
declared  free.  This  has  led  to  such  a  diversity  of  opinion  that  while 
one  expert  claims  that  the  disease  exists  in  every  vineyard  in  the 
State,  another  would  have  us  believe  that  no  such  disease  exists  at  all, 
and 'that  all  cases  of  dying  vines  can  be  ascribed  to  one  or  other  of  the 
recognized  vine  diseases. 

Neither  of  these  extreme  views  seem  to  explain  completely  the 
observed  facts.  While  many  cases  of  supposed  Anaheim  have  proved 
to  be  nothing  but  Phylloxera,  root-rot,  vine-hopper,  drought,  etc.,  there 
still  remain  a  large  number  of  unexplained  cases. 

In  some  cases  the  symptoms  are  practically  identical  with  those  of 
some  of  the  "physiological"  diseases  which  affect  vine  diseases  in 
Europe.  Typical  cases  of  Eougeot  .have  been  noted  in  Contra  Costa 
County,  of  Brunissure  in  San  Joaquin,  and  of  Folletage  in  Fresno, 
Kings,  and  other  counties.  In  Sonoma  County  the  disease  of  Red-leaf, 
which  has  some  analogy  with  Anaheim,  has  been  studied  by  Mr.  0. 
Butler.  An  account  of  these  diseases  may  be  found  in  Bulletin  168, 
entitled  '  *  Observations  on  Some  Vine  Diseases  in  Sonoma  County. ' ' 

In  a  general  way,  as  these  troubles  are  due  to  soil  and  climatic  con- 
ditions which  weaken  the  vine,  they  are  to  be  combated  by  cultural 
methods  which  tend  to  invigorate.  Shorter  pruning,  thorough  culti- 
vation, irrigation  or  drainage,  and  fertilization  will  in  most  cases  be 
effective  in  curing  vines  which  are  not  too  far  gone. 

Many  cases  have  been  brought  to  the  attention  of  the  station  during 
the  last  two  years,  in  which  vines  which  were  apparently  healthy  the 
previous  year  have  failed  to  bud  out  in  the  spring,  or  budded  out 
weakly  and  very  late.  The  cause,  in  most  cases,  seemed  to  be  some 
injury  to  the  vines  during  the  growing  season  of  the  previous  year. 
This  cause  was  in  many  cases  the  attacks  of  vine-hoppers.  Black 
Prince  vines  growing  in  Tokay  vineyards  have  very  often  been  killed. 
This  seems  to  be  because  the  vine-hoppers,  having  a  special  fondness 
for  this  variety,  congregate  in  large  numbers  on  such  isolated  vines. 
Whenever  the  hoppers  are  sufficiently  abundant  to  cause  the  dropping 
of  the  leaves  in  summer,  the  vine  fails '  to  ripen  its  wood  properly. 


BULLETIN  197. 


GRAPE    CULTURE    IN    CALIFORNIA. 


151 


Without  mature  green  leaves  the  buds  and  canes  do  not  receive  the 
stores  of  starch  which  they  need  for  the  new  growth  in  spring,  and 
will  either  grow  poorly  the  following  year  or  fail  to  start  at  all. 

When  a  new  growth  of  leaves  in  autumn  follows  summer  defoliation 


FIG.  15.     Brunissure  on  Tokay  leaves. 

by  hoppers,  mildew,  or  other  causes,  the  effect  is  even  worse.  The  new 
shoots  which  start  exhaust  what  food  reserves  the  vine  possesses, 
and  the  leaves  are  killed  by  the  early  winter  frosts  before  they  have 
been  able  to  return  the  supplies  they  have  taken  from  the  canes. 
Similar,  but  less  severe,  effects  have  been  observed  following  a  bad 
attack  of  Oidium. 


152 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


This  starvation  of  the  canes  and  buds  may  be  brought  about  in 
another  way,  namely,  by  the  production  of  too  large  a  crop.  It  is 
often  possible,  by  excessively  long  pruning,  to  cause  a  vine  to  produce 

an  abnormally  large  crop  of 
grapes.  The  larger  the  crop  the 
more  material  it  takes  from  the 
vine,  and  if  too  large,  the  vine  is 
unable  to  support  it  and  at  the 
same  time  lay  up  reserve  mate- 
rials in  its  canes  and  buds.  In 
consequence,  an  extra  large  crop 
is  often  followed  by  weak  growth 
in  the  spring,  and  a  consequent 
small  crop  the  following  autumn. 
Vines  of  heavy  bearing  varieties 
may  even  be  killed  in  this  way, 
by  repeated  long  pruning. 

This  fact  has  been  long  recog- 
nized by  practical  grape-growers. 
Lately,  Professor  L.  Ravaz,1  of 
the  National  School  of  Agricul- 
ture at  Montpellier,  France,  has 
advanced  the  opinion  that  the 
death  of  vines,  as  a  consequence 
of  overbearing,  is  much  com- 
moner than  is  usually  supposed. 
This  overbearing  may  occur  as  a 
consequence  of  various  condi- 
tions other  than  long  pruning. 
Some  seasons  are  peculiarly 
favorable  to  heavy  crops.  Cer- 
tain diseases  and  injuries  induce 
temporary  heavy  bearing.  What- 
ever the  cause  of  abnormally 
heavy  crops,  Professor  Ravaz 
believes  that  they  may  result  in 
the  death  of  vines.  This  is  the 
FIG.  IG.  Biaek  Knot  on  2-year-oid  zinfandei.  explanation  he  gives  of  the  death 

of  large  numbers  of  vines  in  southern  France,  Algeria,  and  other 
countries,  and  he  ascribes  our  so-called  Anaheim  disease  to  the  same 
cause. 


1  "Influence  de  la  Surproduction  sur  la  Vegetation  de  la  Vigne,"  by   L.   Ravaz, 
Coulet  et  fils,  Montpellier,  1906. 


BULLETIN  197.  GRAPE    CULTURE    IN    CALIFORNIA.  153 

This  is  substantially  the  explanation  given  of  the  dying  of  vines  in 
Santa  Clara,  in  Bulletin  134,  which  was  published  before  the  region 
was  declared  infested  by  Anaheim  disease.  Whether  this  explanation 
is  sufficient  is  still  doubtful,  though  it  is  rendered  probable  by  the 
fact  that  healthy  young  vineyards  are  now  growing  in  Santa  Clara, 
on  the  same  soil  where  vines  have  been  killed  by  ' '  Anaheim  disease. ' ' 


FK;.  17.    Bluck  Knot  on  arm  of  old  vine. 

Black  Knot. — This  is  one  of  the  commonest  and  most  widely  dis- 
tributed diseases  of  the  vine  in  California.  Many  specimens  are  received 
by  the  Experiment  Station  every  year,  from  nearly  all  vine -growing 
sections.  It  consists  of  peculiar  growths,  or  swellings,  usually  near  the 
surface  of  the  ground  on  the  upper  parts  of  the  roots  or  the  lower  part 
of  the  trunk.  It  often  occurs,  also,  on  all  parts  of  the  trunk  and 
branches,  but  only  rarely  on  the  canes. 

As  a  rule  it  does  little  damage  unless  it  occurs  on  young  vines, 
or  attacks  old  vines  very  severely.  Figure  16  is  the  photograph  of 


154 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


a  young  vine  very  badly  attacked,  showing  a  large  mass  of  knots  at  the 
surface  of  the  ground,  and  four  on  the  stem  above  the  surface.  Such 
a  vine  is  almost  girdled  and  could  never  develop  into  a  healthy  plant. 
Figure  17  shows  the  appearance  of  the  knot  on  a  branch  or  arm.  In 

this  case  the  knots  could  be 
removed  and  the  vine  might 
recover  perfectly^ 

It  is  not  uncommon  to  find 
vines  with  large  masses  of 
knots  on  all  sides  of  the  trunk 
and  on  all  the  arms,  which 
yet  make  a  vigorous  growth 
and  produce  good  crops. 
When  the  knots  extend  all 
around  the  trunk  of  an  old 
vine,  however,  it  may  be 
girdled,  and,  while  it  seldom 
dies,  it  may  become  weak  and 
worthless. 

Various  theories  have  been 
advanced  as  to  the  cause  of 
this  disease,  but  the  most  com- 
monly accepted  is  that  it  is 
due  to  abrupt  changes  of  tem- 
perature, and  especially  to 
autumn  frost  occurring  before 
the  vine  has  become  thor- 
oughly dormant.  This  cause 
alone,  however,  does  not  seem 
to  be  sufficient  to  cause  the 
disease.  The  knots  appear 
only  on  vines  growing  in 
moist  places,  and  especially 
in  sandy  soil  in  the  hotter 
regions. 

Anything  which  causes  a 
vine  to  grow  vigorously  late 
in  the  season  and  prevents  the  proper  ripening  of  the  wood,  renders  it 
susceptible  to  the  disease. 

In  accordance  with  these  ideas,  the  remedies  advocated  aim  at  caus- 
ing the  vine  to  ripen  its  wood  early  and  completely.  These  remedies 
•are  drainage  of  the  soil,  fertilization  with  phosphatic  manures,  longer 
pruning,  raising  the  trunk  of  the  vine,  and  removal  of  the  knots. 


FIG.  18.    Coulured  bunch  of  Muscat  of  Alexandria. 


BULLETIN  197. 


GRAPE    CULTURE    IN    CALIFORNIA. 


155 


Swabbing  with  lime,  sulfate  of  iron,  and  other  antiseptics  has  proven 
useless. 

Couture  of  Muscats. — The  Muscat  of  Alexandria,  from  which  the 
bulk  of  our  raisins  is  made,  has  a.  tendency  to  drop  its  blossoms  without 
setting.  This  trouble  is  usually  known  in  California  by  the  French 
term  of  "coulure,"  which  may  be  translated  "dropping."  The  first 
crop  is  particularly  subject  to  this  defect,  which  is  often  so  serious 
that  a  large  part  and  sometimes  the  whole  of  the  first  crop  is  lost. 

The  trouble  has  been  investigated  during  the  last  twenty-five  years 
by  a  large  number  of  observers,  and  various  causes  assigned.  Among 
these  causes  may  be  mentioned  unfavorable  weather,  improper  prun- 
ing, fungous  attacks,  unsuitable  or  exhausted  soil.  These  causes  and 
others  may  intensify  the 
trouble,  but  the  primary  and 
essential  cause  has  lately 
been  demonstrated  by  P. 
Viala  and  P.  Pacottet,  and 
published  in  the  "Revue 
de  Viticulture."1 

According  to  these  investi- 
gations the  cause  of  the 
dropping  lies  in  the  peculiar 
structure  of  the  flower  itself. 

The  flowers  of  most  culti- 
vated varieties  of  grapes  are 
what  the  botanist  calls  * '  per- 
fect." That  is,  each  flower  has  the  two  elements  which  are  necessary 
for  the  development  of  the  perfect  fruit.  These  elements  are  the  pollen 
contained  in  the  anthers  and  the  ovules  contained  in  the  pistil.  Unless 
the  ovules  are  fertilized  by  normal  pollen  the  pistil  will  not  develop 
into  a  normal  grape  berry. 

There  are  several  defects  in  the  Muscat  flower  which  make  this 
necessary  pollination  more  uncertain  than  with  most  varieties,  and  it 
is  only  under  the  most  favorable  conditions  that  the  ovules  are  prop- 
erly fertilized. 

In  the  first  place,  owing  to  the  shortness  of  the  filaments  supporting 
the  anthers,  the  position  of  the  pollen  is  such  that  it  may  all  fall  off 
without  reaching  the  stigma,  which  is  a  part  of  the  pistil  through 
which  the  pollen  tube  obtains  access  to  the  ovule. 

In  the  second  place,  the  pollen  is  not  powdery  as  with  most  vines, 
but  waxy  and  with  a  tendency  to  cohere  in  masses.  This  renders  its 


A  B  C 

FIG.  19.    (After  Viala  and  Pacottet.) 

Normal  flower  of  the  vine,  with  filaments  as  long 

as  the  pistil. 
Defective  flower  of  the  vine,  with  filaments  shorter 

than  the  pistil. 
Defective  flower  of  the  vine,  with  abortive  pistil. 


1  "Sur   la  Fgcondation  Artificielle  de  la  Vigne,"  Revue  de  Viticulture,  T.  XXII, 
No.  551,  pp.  5-10.     Paris,  1904. 


156 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


distribution  by  wind  and  insects  much  less  certain.  The  pollen  grains 
are,  moreover,  often  imperfect,  and  most  of  them  are  incapable  of 
germination  and  performing  their  function,  even  if  they  reach  the 
stigma. 

This  is  shown  when  we  place  the  pollen  grains  in  a  weak  sugar 
solution.     Normal  pollen  germinates  readily  in  such  a  solution,  but 

that  of  Muscat  of 
Alexandria  germi- 
nates irregularly, 
imperfectly,  or  not 
at  all.  The  same 
result  occurs  if  the 
pollen  is  placed  on 
the  stigma  of  any 
variety  of  vine. 

Remedies.  -  -  In 
regions  where  this 
variety  has  been 
grown  for  centu- 
ries (Asia  Minor, 
northern  Africa, 
Spain)  it  is  usual 
to  plant  other 
varieties  having 
abundant  and 
strong  pollen 
among  the  Muscat 
vines.  This  prac- 
tice, while  not  re- 
moving the  trouble 
completely,  may  be 
of  use  in  Califor- 
nia. It  would  be 
well  in  planting  a 
Muscat  vineyard  to 
make  use  of  some 
of  the  varieties  which  have  shown  their  ability  to  produce  abundant 
and  vigorous  pollen.  The  proof  of  this  is  regular  setting  of  abundant 
crops.  The  pollinating  varieties  might  be  planted  in  neighboring  blocks, 
or,  better  still,  in  occasional  rows. 

It  is  necessary  not  only  that  the  pollinating  varieties  should  have 
good  pollen,  but  that  they  should  blossom  at  the  same  time  as  the 


FIG.  20.    Four-year  old  Muscat  of  proper  form. 


BULLETIN  197 


GRAPE    CULTURE    IN    CALIFORNIA. 


157 


Muscat.  In  accordance  with  the  advice  of  Viala  and  Pacottet,  the 
pollen  of  Aramon  X  Rupestris  has  been  used  with  success  in  the  hot- 
houses of  Paris  for  the  artificial  fecundation  of  Muscat  flowers.  This 
is  a  resistant  stock  which  produces  an  abundance  of  blossoms  which 
are  completely  staminate,  and  therefore  incapable  of  producing  fruit 
themselves.  Their  pollen,  however,  is  extremely  vigorous,  and  causes 
the  fruit  of  other  varieties  to  set  well.  The  pollen  of  this  variety  is 
collected,  dried,  and,  at  the  proper  time,  dusted  on  to  the  Muscat 
blossoms.  As  this  variety  blossoms  about  two  weeks  earlier  than  the 


FIG.  21.    Six-year-old  Muscat  of  usual  form. 

Muscat,  however,  it  could  not  be  used  for  cross-pollination  unless 
the  pollen  were  collected  and  applied  as  described,  which  is  of  course 
impracticable  in  a  vineyard. 

Most  of  the  varieties  cultivated  in  the  raisin  districts  blossom  about 
the  same  time  as  the  Muscat,  and  such  varieties  as  Palomino,  Perruno, 
Beba,  and  Burger,  which  always  set  their  fruit  well,  would  be  suitable 
for  the  purpose. 

Another  peculiarity  of  the  Muscat  of  Alexandria,  noted  by  Viala 
and  Pacottet,  is  that  the  stigma  of  the  pistil  is  covered  with  a  drop 
of  liquid  which  forms  and  falls  two  or  three  times  a  day,  thus  removing 
pollen  grains  which  may  have  reached  the  stigma.  A  moist  atmosphere 
is,  therefore,  unfavorable  to  the  setting  of  Muscat. 


158 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


We  can  control  the  moisture  conditions  to  some  extent  by  avoiding 
cultivation  or  irrigation  during  and  just  before  blossoming. 

The  air  near  the  ground  is  moister  than  that  a  little  higher  up,  and 
the  practice  of  pruning  Muscats  to  a  low,  prostrate  stump  is  unfavorable 
for  this  and  for  other  reasons. 

A  Muscat  vine,  like  any  other,  should  have  a  distinct  stem  or  trunk. 
This  trunk  should  be  smooth  and  without  spurs  or  scars.  This  trunk 


FIG.  22.    Low  Muscat  raised  by  pruning. 

makes  it  possible  to  plow,  cultivate,  and  hoe  close  to  the  vine  without 
injuring  the  arms  and  spurs.  It  facilitates  the  removal  of  suckers 
from  below  the  ground,  and  holds  the  bearing  wood  high  enough  up  to 
keep  the  grapes  from  touching  the  ground.  How  high  this  trunk 
should  be  depends  on  various  conditions.  A  smooth  stem  twelve  inches 
in  length  from  the  surface  of  the  ground  to  the  branching  of  the  arms 
is  sufficient  to  give  the  advantage  mentioned. 


UNIVERSITY  OF    CALIFORNIA    PUBLICATIONS. 

COLLEGE  OF  AGRICULTURE. 

AGRICULTURAL  EXPERIMENT  STATION, 

BERKELEY,  CALIFORNIA. 


THE  GRAPE  LEAF-HOPPER. 

BY  H.  J.  QUAYLE. 


BULLETIN     No.     198. 

(Berkeley,  Cal.,  July,  1908.) 


SACRAMENTO: 

w.  w.  SHANNON,     :     :     :     :     SUPERINTENDENT  STATE  PRINTING 

1908. 


BENJAMIN  IDE  WHEELER,   Ph.D.,  LL.D.,  President  of  the   University. 


EXPERIMENT  STATION  STAFF. 

E.  J.  WICKSON,  M.A.,  Director  and  Horticulturist. 

E.  W.  HILGARD,  Ph.D.,  LL.D.,  Chemist. 

W.  A.  SETCHELL,  Ph.D.,  Botanist. 

EL  WOOD  MEAD,  M.S.,  C.E.,  Irrigation  Engineer.      (Absent  on  leave.) 

LEROY  ANDERSON,  Ph.D.,  Dairy  Industry  and  Superintendent  University  Farm. 

M.  E.  JAFFA,  M.S.,  Nutrition  Expert,  in  charge  of  the  Poultry  Station. 

C.  W.  WOODWORTH,  M.S.,  Entomologist. 

R.  H.  LOUGHRIDGE,  Ph.D.,  Soil  Chemist  and  Physicist. 

G.  W.  SHAW,  M.A.,  Ph.D.,  Agricultural  Technologist,  in  charge  of  Cereal  Stations. 

GEORGE  E.   COLBY,  M.S.,   Chemist,  in  charge  of  Agricultural  Chemical  Laboratory. 

RALPH  E.  SMITH,  B.S.,  Plant  Pathologist  and  Superintendent  of  Southern  California 

Pathological  Laboratory  and  Experiment  Station.      Whitticr. 
A.   R.  WARD,   B.S.A.,   D.V.M.,   Veterinarian  and  Bacteriologist. 
E.  W.  MAJOR,   B.Agr.,  Animal  Industry. 
H.  M.  HALL,  M.S.,  Assistant  Botanist. 

H.  J.  QUAYLE,  A.B.,  Assistant  Entomologist.     Whittier. 
W.    T.    CLARKE,    B.S.,    Assistant    Horticulturist    and    Superintendent    of    University 

Extension  in  Agriculture. 

JOHN  S.  BURD,  B.S.,  Chemist,  in  charge  of  Fertiliser  Control. 
C.  M.  HARING,  D.V.M.,  Assistant  Veterinarian  and  Bacteriologist. 
H.  A.  HOPPER,  B.S.A.,  Assistant  in  Dairy  Husbandry. 
J.  H.  NORTON,  M.S.,  Assistant  Chemist  in  charge  Fertilizer}      Citrus  Experiment 

T.  PEOTNTCTBSS.,  Assistant  Horticulturist,  \          Stati°n- 


E.  B.  BABCOCK,  B.S.,  Assistant  Plant  Pathologist. 

E.  H.  SMITH,  M.S.,  Assistant  Plant  Pathologist. 

F.  L.  YEAW,  B.S.,  Assistant  Plant  Pathologist. 

H.  J.  RAMSEY,  M.S.,  Assistant  Plant  Pathologist,)        Southern  California  Patholog- 

C    O    SMITH,   M.S.,  "  "  "  )  ical  Laboratory,  Whittier. 

R.  E.  MANSELL,  Assistant  in  Horticulture,  in  charge  of  Central  Station  Grounds. 

RALPH  BENTON,  B.S.,  B.L.,  Assistant  in  Entomology   (Apiculture). 

A.  J.  GAUMNITZ,  M.S.,  Assistant  in  Cereal  Investigations. 

RACHAEL  CORR,  M.^..,  Assistant  in  Cereal  Laboratory. 

HANS  C.  HOLM,  B.S.,  Assistant  in  Zymology. 

P.  L.  McCREARY,  B.S.,  Laboratory  Assistant  in  Fertilizer  Control. 

F.  E.  JOHNSON,  B.  L.,  Assistant  in  Soil  Laboratory. 

M.  E.  STOVER,  B.S.,  Assistant  in  Agricultural  Chemical  Laboratory. 

D.  R.  HOAGLAND,  A.B.,  Assistant  in  Agricultural  Chemical  Laboratory. 
CHARLES  FUCHS,  Curator  Entomological  Museum. 

P.  L.  HIBBARD,  B.S.,  Assistant  Fertilizer  Control  Laboratory. 

M.  E.  SHERWIN,  Field  Assistant  in  Agronomy. 

W.  H.  VOLCK,  Field  Assistant  in  Entomology.     Watsonville. 

E.  L.  MORRIS,  B.S.,  Field  Assistant  in  Entomology.     San  Jose. 
J.  S.  HUNTER,  Field  Assistant  in  Entomology.     San  Mateo. 

D.  L.  BUNNELL,  Clerk  to  the  Director. 


JOHN  TUOHY,  Patron,  )  Tulare  Substation,  Tulare. 

J.  T.  BEARSS,  Foreman,  \ 

J.  W.  ROPER,  Patron,  )  University  Forestry  Station,  Chico. 

E.  C.  MILLER,  In  charge,  ) 


™A  University  Forestry  Station,  Santa  Monica. 

N.  D.  INGHAM,  Foreman,    ) 

VINCENT     J.     HUNTLEY,     Foreman     of     California    Poultry     Experiment     Station, 
Petaluma. 

The  Station  publications  (REPORTS  AND  BULLETINS),  so  long  as  avail- 
able, will  be  sent  to  any  citizen  of  the  State  on  application. 


OUTLINE. 


PAGE. 
GENERAL   CONSIDERATIONS 177 

Early   accounts ;    Destructiveness ;   Distribution,   general,    local. 

LIFE  HISTORY  AND  HABITS 181 

OVERWINTERING  ADULTS 181 

Food  habits ;  Relation  of  food  to  development  and  activity ;  Influence  of 
temperature  upon  activity  ;  Proportion  of  the  sexes ;  Migrations  ;  Time  they 
attack  the  vine  ;  Do  they  feed  exclusively  on  the  vine ;  Habits  on  the  vine  ; 
Copulation  and  oviposition. 

THE  EGG   3SG 

Description  and  appearance ;  Where  laid ;  Number ;  Rate  of  egg  laying ; 
Incubation  period ;  Percentage  of  eggs  that  hatch ;  Effect  of  oviposition 
upon  the  leaf. 

THE  NYMPH   102 

The  hatching  process ;  First  stage ;  Second  stage ;  Third  stage :  Fourth 
stage ;  Fifth  stage  ;  Moulting ;  Habits  of  feeding ;  Transfer  'to  other  food 
plants. 

THE  ADULT   19G 

Time  of  reaching  maturity ;  Feeding  habits ;  Copulation  and  oviposition ; 
Activity  and  migrations  ;  Activity  of  the  sexes  ;  Proportion  of  the  sexes  ; 
Differences  in  coloring;  The  varieties  of  the  species  comes  :  Proportion  of  the 
varieties ;  Common  name  of  the  insect ;  Preferences  for  different  varieties  of 
vines. 

DEVELOPMENT 200 

Length  of  life  cycles  ;  Number  of  generations  ;  Comparisons  of  development 
in  other  localities. 

NATURAL  CONTROL .   202 

Climatic  ;  Parasitic  ;  Predatory  ;  Fungous. 

MECHANICAL   CONTROL    203 

Blowers  and  suction  ;  Torches ;  Dry  powders  ;  Sticky  shields  ;  Fumigation  ; 
Sprays  and  washes ;  Screens  or  cages. 

FARM   PRACTICES 214 

Plowing ;  Sheeping. 

SUMMARY    215 

LITERATURE   .  .   217 


THE  GRAPE  LEAF-HOPPER 

(Typlilocy'ba  comes  Say.) 

BY  H.  J.  QUAYLE. 


GENERAL  CONSIDERATIONS. 

Early  Accounts. — The    grape    leaf -hopper    was    first    named    and 
described  by  Thomas  Say1  in  the  year  1825.     Specimens  were  taken 


Fig.   1.     Grape  leaf  showing  first  indication  of  injury  due  to  hoppers.     The 
white    specks    represent   where   the    insects    have   been    feeding. 

that  year  from  Missouri,  and  three  or  four  years  later  it  was  reported 
as  an  important  pest  of  the  vine  in  Massachusetts.  Harris2  in  1841 
wrote  the  first  complete  account  of  the  insect  and  fully  appreciated 

'Jour.  Acad.  of  Nat.  Sciences.  Phil,  iv,  327. 
2  Harris.  Ins.  Inj.  to  Vegetation,  Flint  Ed..  227. 


178 


UNIVERSITY   OF    CALIFORNIA EXPERIMENT    STATION. 


the  injury  caused  by  it,  and  ever  since  that  time  it  has  occupied  a 
very  important  place  in  the  literature  of  grape  insects  in  this  country. 
Harris's  account  of  the  insect  remained  the  standard  for  a  long- 
while,  and  no  very  thorough  work  was  done  on  the  life  history  of 
the  insect  until  it  was  undertaken  by  Slingerland  in  1901. x 

In  California  it  has  been  reported  as  a  pest  of  the  vine  since  1875. 
The  accounts  of  insects  in  the  "Pacific  Rural  Press"  furnish  a 
fairly  good  index  on  the  occurrence  of  injurious  species  in  this 
State,  and  the  first  account  there  given  is  in  the  issue  of  April  12, 
1879.  Notices  regarding  this  insect  have  appeared  frequently  in 


Fig.  2.  Young  grape  leaves  in  advanced  stage  of  hopper  injury.  These  leaves  had 
completely  dried  up  and  fallen  to  the  ground  in  the  early  spring.  Photographed 
April  20,  1907. 

the  press  of  the  State,  as  well  as  other  publications,  since  that  time. 
Brief  notices  of  its  occurrence  have  been  printed  in  the  State  Horti- 
cultural Commission  reports,  and  a  bulletin  on  the  insect  was  issued 
from  this  station  in  1897. 2 

Destructiveness. — With  the  exception  of  the  phylloxera,  the  vine 
hopper  is  undoubtedly  the  most  destructive  insect  pest  of  the  vine 
in  the  State.  It  is  more  uniformly  present  than  any  other  insect 

1  Slingerland,  Cornell  Exp.  Sta.  Bull.  215. 

2  Woodworth,  Cal.  Agr.  Exp.  Sta.  Bull.  116. 


BULLETIN  198. 


THE  GRAPE  LEAF-HOPPER. 


179 


attacking  the  vine,  and  each  year  in  some  parts  of  the  State  it 
occurs  in  very  great  numbers,  and,  in  such  sections,  it  levies  a  heavy 
tax  upon  the  vineyard  interests.  To  give  expression  to  this  loss  in 
money  value,  for  example,  in  one  vineyard  of  about  a  thousand 
acres  near  Madera,  the  owner  estimated  that  the  damage  done  last 
year  by  hoppers  would  aggregate  about  $10,000. 

The  grape  leaf-hopper  belongs  to  the  class  of  injurious  insects 
that  obtain  their  food  by  sucking  the  juices  from  the  plant.  Scale 
insects  and  plant  lice  are  other  well  known  pests  belonging  to  this 
same  general  group,  which  obtain  their  food  in  much  the  same  way 
that  the  mosquito  sucks  our  blood.  The  sharp  pointed  beak  or 
proboscis  of  the  hopper  (Fig.  4)  is  thrust  into  the  tissues  of  the 
grape  leaf  and  the 
liquid  parts  extract- 
ed therefrom.  The 
feeding  is  done 
mostly  on  the  un- 
derside of  the  leaf, 
and  those  leaves 
around  the  base  of 
the  vine  are  the 
ones  first  attacked. 

The  first  indica- 
tion of  their  work 
is  a  mottled  appear- 
ance of  the  leaf  due 
to  the  pale  spots 
formed  wherever  the 
beak  has  been  in- 
serted and  the  green  parts  taken  out  (Fig.  1) .  As  the  feeding  continues 
these  spots  become  more  numerous,  and  this  pale  yellow  color 
spreads  over  the  entire  surface;  and  finally  the  leaf  turns  brown 
and  drops  off  (Fig.  2).  This  injury  has  been  observed  as  early 
as  April  or  May,  and  thus  the  vine  from  the  very  beginning 
of  the  season  is  prevented  from  making  its  normal  growth.  As 
the  hoppers  increase  in  numbers  the  injury  increases  with  the 
advancement  of  the  season.  In  midsummer  quite  a  large  area 
about  the  crown  of  the  vine  will  show  all  the  leaves  pale  colored  or 
completely  dried  up,  and,  in  severe  cases,  the  entire  vine  is  thus 
affected.  This  drying  up  and  dropping  off  of  the  leaves  allows  the 
sun  to  have  free  access  to  the  fruit  and  may  cause  sunburn.  We  have 
seen  the  fruit  thus  exposed  and  badly  sunburned  as  early  as  the 
middle  of  June.  The  falling  off  of  the  leaves  prematurely  also  pre- 


Fig.  3.  The  foliage  and  fruit  of  the  grape  is  often  badly 
smutted  by  the  excrement  of  hoppers.  The  black 
specks  on  the  above  leaf  indicate  this. 


180 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


labrum 


labium 


vents  the  berry  from  maturing  properly  since  it  is  in  the  leaves  of 
the  plant  that  the  sugar  of  the  berry  is  manufactured.  The  grape 
thus  loses  much  of  its  flavor  and  sweetness,  and  likewise  the  char- 
acteristic coloring,  which  is  so  desirable  in  certain  table  varieties,  is 
not  attained.  The  fruit,  furthermore,  is  badly  smutted  by  the  exuda- 
tions of  the  insects,  and  this  serves  as  a  harboring  place  for  the 
collection  of  dust  and  dirt,  and  for  the  growth  of  fungi  (Fig.  3). 

The  dropping  of  the  leaves  or  any 
interference  with  their  normal  func- 
tions likewise  has  its  effect  on  the 
growth  of  the  wood  of  the  vine.  The 
canes  fail  to  ripen  normally  for  the 
next  year's  wood,  and  many  of  the 
buds  fail  to  develop  in  the  following 
spring.  The  vine  may  thus  be  more 
or  less  permanently  stunted  in  growth, 
and  even  killed  in  severe  cases  of 
Mandibles  grape  leaf -hopper  injury. 

Distribution;  General. — The  grape 
leaf -hopper  (Typhlocyba  comes  Say) 
is  a  widely  distributed  native  Ameri- 
can insect  occurring  in  the  United 
States  practically  wherever  the  vine  is 
grown.  It  is  frequently  notably  in- 
jurious in  the  grape  belts  of  New 
York  and  Ohio,  as  well  as  other  less 
important  grape  sections  in  this 
country.  In  Europe  this  species  is 
replaced  by  two  other  related  species, 
Typhlocyba  flavescens  and  Typhlocyba 
viticola.  The  former  seems  to  be  the 
Much  en-  m0re 'injurious  of  the  two  and  occurs 
throughout  all  of  temperate  Europe 

and   northern   Africa,   while   the   latter   is    confined   mostly   to   Italy 

and   the   neighboring   islands.1 

Local. — In  California  our  species  is  found  in  practically  all  of  the 
vine  growing  sections,  but  is  most  injurious  in  the  Sacramento  and 
San  Joaquin  valleys.  In  the  coast  valleys  another  larger  species 
(Tettegonia  atropunctata)  is  frequently  injurious,  most  commonly 
during  the  earlier  part  of  the  season.  This  species  appears  not  to 
feed  exclusively  on  the  vine,  and  during  midsummer  and  later  is 


\  Maxillae 


Fig.  4.     The  beak,  or  mouth-parts,  of 
the    grape    leaf-hopper, 
larged. 


1  Mayet's  Insectes  de  la  Vigne,  168. 


BULLETIN  198.  THE  GRAPE  LEAF-HOPPER.  181 

distributed  over  other  food  plants.  During  1907  the  grape  leaf-hopper 
was  particularly  abundant  in  many  of  the  vineyards  about  Fresno, 
and  also  in  the  lower  part  of  the  San  Joaquin  Valley  around  Lodi. 


LIFE  HISTORY  AND  HABITS. 

OVERWINTERING    ADULTS. 

During  the  colder  weather  of  winter  the  hoppers  may  be  found  in 
large  numbers  in  the  leaves  or  rubbish  in  the  vineyard,  or  along  the 
bordering  roadsides  and  fences.  Where  leaves  have  been  blown  together 
in  bunches  or  lodged  in  weeds  or  grass  over  the  vineyard  or  its  borders, 
hoppers  will  be  especially  likely  to  be  present  during  the  colder  or 
wet  rainy  days  of  the  winter  season.  They  will  also  be  found  harbor- 
ing low  down  along  the  fences  or  in  the  weeds  or  other  growth  among 
the  vines.  Alfilaria,  one  of  the  commonest  plants  in  many  California 
vineyards  in  winter,  forms  a  close  rosette  on  the  ground,  and  hoppers 
will  be  found  abundantly  under  the  low  spreading  foliage  of  this 
plant. 

Food  Habits. — The  grape  leaf-hopper  feeds  on  a  large  variety  of 
plants  during  the  winter  season.  It  will  be  found  feeding  chiefly 
during  the  warmer  days  of  winter,  and  resting  more  or  less  dormant 
during  the  colder  or  rainy  weather.  It  attacks  practically  everything 
that  may  be  growing  in  the  vineyard  or  vicinity,  although  a  preference 
is  shown  for  certain  plants.  Alfilaria  is  readily  attacked  by  these 
insects,  and  where  hoppers  are  numerous  the  foliage  of  this  plant  will 
be  seen  to  have  a  pale  yellow  color  as  a  result  of  their  work.  The  low 
spreading  foliage  seems  to  offer  suitable  conditions  for  the  hoppers 
when  they  are  not  feeding,  so  that  they  will  be  found  on  the  underside 
of  these  plants  almost  continuously,  regardless  of  the  kind  of  weather. 
Burr  clover  is  also  readily  attacked  by  the  hoppers  in  winter,  as  well 
as  rag  wee£,  dock,  wild  mustard,  alfalfa,  and  several  kinds  of  grains 
and  grasses.  They  show  a  preference,  however,  for  such  plants  as  the 
alfilaria  and  the  clovers  as  against  the  grains  and  grasses. 

The  hoppers  that  were  taken  into  the  laboratory  in  the  early  spring 
invariably  died  in  the  course  of  two  or  three  days  if  deprived  of  food. 
Under  the  same  conditions  they  were  easily  maintained  upon  alfilaria 
or  other  food.  They  were  confined  in  lantern  globes  which  were  placed 
in  the  open  window  of  the  laboratory,  so  that  the  conditions  as  regards 
temperature  and  moisture  were  not  very  different  from  that  of  the 
vineyard.  Hoppers  were  also  confined  in  lantern  globes  in  the  vineyard, 
but  in  all  cases  they  died  very  soon  without  food,  though  the  more 
dormant  they  were  the  longer  they  were  able  to  survive. 


182  UNIVERSITY   OF    CALIFORNIA EXPERIMENT    STATION. 

Many  of  the  hoppers  succumbed  to  long  continued  wet  weather  or 
other  unusual  conditions  in  winter.  After  about  two  weeks  of  almost 
continuous  rain  we  have  counted  as  many  as  700  dead  hoppers  under 
a  single  bunch  of  alfilaria.  This  mortality  may  be  partly  accounted  for 
because  of  unsuitable  conditions  for  obtaining  food,  though  the  direct 
effect  of  exposure  to  such  conditions  is  probably  the  more  important 
factor. 

Relation  of  Food  to  Development  and  Activity. — The  activity  of  the 
insects  is  dependent  primarily  upon  food  and  temperature,  and  the 
latter  largely  influences  the  former.  No  matter  how  much  nutritious 
food  may  be  available,  if  the  temperature  is  sufficiently  low  they  become 
dormant  and  are  revived  only  upon  the  rise  of  temperature;  but  once 
they  become  active  through  the  influence  of  a  higher  temperature,  they 
require  food  to  maintain  their  activity. 

Influence  of  Temperature  upon  Activity. — On  the  warm  days  of 
winter  the  hoppers  are  very  active  and  fly  up  in  large  numbers  before 
a  person  as  he  walks  through  the  vineyard.  On  the  contrary,  on  a 
cold  or  wet  day  they  may  only  be  disturbed  by  actually  moving  the 
object  upon  which  they  are  resting,  and  then  they  will  fly  but  a  very 
short  distance, — not  more  than  a  foot  or  two  generally.  It  is  possible 
during  such  days  to  pick  up  the  leaves,  with  a  dozen  or  more  hoppers 
resting  on  the  under  surface,  and  place  them  in  a  cyanide  bottle  without 
disturbing  them.  They  are  most  active  during  the  warmer  portions  of 
the  day, — from  nine  or  ten  o'clock  in  the  morning,  when  the  dew  is 
dried  from  the  leaves,  until  three  or  four  in  the  afternoon. 

Experiments  carried  on  in  the  laboratory  to  determine  the  effect  of 
temperature  on  overwintering  adults  indicated  that  a  temperature  of 
110°  F.  was  nearly  always  fatal.  These  experiments  consisted  in  con- 
fining the  hoppers  in  a  double  glass  vial  and  heating  gradually  with 
artificial  heat.  A  small  homo  vial  was  contained  within  a  larger  one, 
and  a  thermometer  extended  through  the  corks  of  both  viate  so  that  the 
bulb  was  contained  in  the  center  of  the  inner  vial  with  the  hoppers. 
Cotton  was  placed  in  the  bottom  of  this  vial  to  prevent  them  from 
coming  in  contact  with  the  glass  when  they  would  fall  down.  The 
whole  apparatus  prevented  so  far  as  possible  the  unequal  heating  of 
the  sides  of  the  vial  as  compared  with  the  air  in  the  interior. 

In  some  of  the  experiments,  as  given  in  the  table  below,  the  tem- 
perature was  first  reduced  by  ice  and  salt  to  30°F.  or  lower,  and 
suddenly  raised  again  to  a  point  at  which  all  the  insects  were  killed. 
By  consulting  the  table  it  will  be  seen  that  they  became  dormant  at 
60°  to  65°F.  and  revived  again  at  about  70°F.  At  80°  to  90°F.  the  first 


BULLETIN  198. 


THE  GRAPE  LEAF-HOPPER. 


of  them  would  be  killed  by  the  heat.  The  optimum  temperature  under 
these  conditions  was  between  70°  and  85°F.  The  temperature  of  the 
room  during  the  experiments  was  between  65°  and  75 °F.  In  most  of 
the  experiments  it  was  the  ordinary  air  of  the  room,  as  regards 
humidity,  but  in  some  a  moist  plug  of  cotton  was  contained  in  the  vial 
with  the  insects,  and  thus  the  humidity  was  considerably  increased. 
The  experiments  in  detail  are  tabulated  below: 

Temperature  Experiments. 


Date. 

Experiments  . 

*» 

<-i  n 

55 
a 

Room  Tem- 
perature   

Inactive  at  .._ 

~§ 

O  ~ 

<o 

If 

Temperature 
Reduced  to 

Active  at  

First  Dead  at. 

I 

i 

& 

fo 

Time  of  Ex- 
periment ... 

1907—  March  20 

1 

7 

66 

0 

o 

o 

o 

85 

110 

3m 

March  20 

2 

8 

66 

90 

110 

4 

March  20 

3 

8 

70 

95 

110 

10 

March  20 

4 

8 

72 

95 

110 

6 

March  20 

5 

8 

72 

100 

110 

5 

March  20 

6 

8 

72 

110* 

120 

5 

March  20 

7 

8 

72 

105* 

115 

6 

March  20 

8 

8 

72 

100* 

110 

8 

March  23 

9 

8 

70 

50 

50-40 

30 

70 

100 

110 

15 

March  23 

10 

7 

68 

60 

50-45 

45 

70 

105 

110 

12 

March  23 

11 

6 

70 

65 

60-50 

35 

76 

87 

102 

10 

March  23 

12 

6 

70 

65-60 

62-55 

25 

74-8 

86 

94 

13 

March  23 

13 

6 

70 

66 

64-56 

30 

64-72 

84 

110 

11 

March  23 

14 

6 

70 

60 

60-54 

40 

57-66 

80 

114 

15 

March  23 

15 

10 

70 

62 

28  1 

65-72 

84 

102 

20 

March  23 

16 

6 

72 

105 

120 

March  23 

17 

7 

72 

100 

110 

March  23 

18 

8 

72 

105 

110 

*  Vial  kept  moist  by  wet  plug  cotton. 


fHeld  for  10m. 


In  the  column  "Inactive  at"  is  indicated  when  the  hoppers  ceased 
moving  about,  and  in  the  column  "Active  at"  when  they  first  regained 
their  locomotive  powers.  The  general  conclusions  suggested  by  these 
experiments  are  as  follows: 

A  rise  in  temperature  to  110°F.,  and  in  one  or  two  cases  to  120°F., 
invariably  killed  the  hoppers.  With  moisture  in  the  tube  they  appeared 
to  withstand  a  slightly  higher  temperature.  Cold  to  as  low  as  25°F. 
had  no  effect  upon  them  except  to  make  them  temporarily  dormant. 
When  they  were  subjected  again  to  the  higher  temperature  they  were 
killed  the  same  as  if  started  from  the  room  temperature,  except, 
apparently,  to  make  the  first  succumb  at  a  lower  temperature.  The 
practical  bearing  of  these  experiments  can  hardly  be  interpreted  beyond 
the  fact  that  a  sudden  rise  in  temperature  may  be  fatal  to  some  of  the 
insects.  In  this  the  rather  unnatural  condition  of  dry,  artificial  heat 
must  also  be  taken  into  consideration. 


184 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


Proportion  of  the  Sexes  of  Overwintering  Hoppers. 


Collected. 

Number  of 
Specimens 
Examined. 

Females. 

Males. 

Percentage 
Females. 

Percentage 

Males. 

March    6th 

1,500 

675 

•      825 

45 

55 

March  28th 

130 

65 

65 

50 

50 

April    12th 

272 

175 

97 

64.4 

35.6 

April    19th 

127 

72 

55 

57 

43 

April    29th  _     _ 

134 

100 

34 

74.6 

25.4 

Totals  and  av.  percentage- 

2,163 

1,087 

1,076 

50.26 

49.74 

Fig.  5.  Tip  of  abdomen  of  female  grape  leaf-hopper, 
showing  ovipositor.  The  black  tipped  appendages, 
the  cerci,  obscure  the  other  parts  of  the  ovipositor 
shown  in  Fig.  6  below.  Greatly  enlarged. 


It  will  be  seen  from  the  average  percentage  in  the  above  table  that 
there  is  practically  no  difference  between  the  numbers  of  the  sexes, 

so  that  we  may  con- 
clude that  both  sexes 
are  able  to  withstand 
the  winter  conditions 
equally  well. 

Migrations. — When 
plowing  is  begun  in 
the  vineyard  in  the 
spring,  before  the 
foliage  appears  on  the 
vine,  the  food  supply 
— consisting  of  what- 
ever vegetation  may 
be  growing  —  is 
turned  under  and 
most  of  the  hoppers  are  obliged  to  look  elsewhere  for  food.  Some  of  the 
insects  remain  in  the  vineyard  and  subsist  upon  what  little  growth  may 
be  left  by  the  plow.  The  larger  number,  however,  must  look  elsewhere 
for  food,  and  this  is  generally  found  in  the  immediate  vicinity,  usually 
around  the  borders  of  the  vineyard.  We  have  seen  all  the  vegetation 
growing  along  the  roadsides  of  badly  infested  vineyards  completely 
deprived  of  the  green  coloring  matter.  After  the  vineyard  was  plowed 
the  hoppers  continued  to  feed  here,  largely,  until  the  vines  came  into 
leaf,  when  they  migrated  back  into  the  vineyards.  These  are  the  only 
distinct  movements  we  have  observed  with  the  overwintering  hoppers 
in  the  spring. 

Time  they  Attack  the  Vine. — The  first  observed  feeding  on  the  grape 
foliage  at  Lodi  during  1907  was  March  28th,  on  an  old  Mission  vine- 
yard that  was  considerably  in  advance  of  the  other  surrounding  vine- 
yards. A  week  or  two  later,  however,  the  foliage  in  many  vineyards 
was  far  enough  along  to  attract  a  good  many  of  the  hoppers  from  their 


BULLETIN  198. 


THE  GRAPE  LEAF-HOPPER. 


185 


varied  winter  food  plants.     In  1908  an  occasional  hopper  was  found 
on  vines  in  the  Sonoma  Valley  as  early  as  March  18th. 

Do  they  Feed  Exclusively  on  the  Vine? — Once  they  begin  to  feed 
upon  the  vine  they  do  not  leave  it  for  other  food  unless,  of  course,  they 
incidentally  happen  to  find  themselves  in  other  situations.  During 
two  or  three  weeks  while  the  vine  is 
coming  into  foliage,  some  hoppers  may 
be  found  on  the  vine  and  others  on 
the  winter  food  plants,  but  those  that 
are  still  feeding  on  the  other  vegeta- 
tion have  not  yet  found  their  way  to 
the  vines.  It.  may  be  a  couple  of 
weeks  after  the  first  foliage  appears, 
therefore,  before  all  the  hoppers  will 
be  found  on  the  vine ;  but,  once  they 
begin  to  feed  on  the  grape,  they  remain  until  the  vine  becomes  dormant 
at  the  end  of  the  season. 

Habits  on  the  Vine. — While  the  leaves  are  still  expanding  and  not 
yet  affording  much  protection  the  hoppers  will  be  found  most  commonly 

on  the  concave  side  of  the  leaves  that 
are  not  yet  fully  expanded,  or  on  the 
leaves  near  the  base  of  the  vine,  where 
they  are  not  so  completely  exposed. 
At  this  period  they  were  not  observed 
to  move  about  to  any  extent,  and 
seemed  to  be  pretty  well  occupied 
with  feeding. 


Fig.  6.  The  two  pairs  of  valves  of  the 
ovipositor  with  which  the  insect 
inserts  its  egg  into  the  leaf  tissues. 
Greatly  enlarged. 


Copulation  and  Oviposit  ion.  —  On 
April  30,  1907,  they  were  observed 
pairing  for  the  first  time.  This  was 
approximately  three  weeks  after  they 
had  begun  to  feed  upon  the  vines. 

The  first  eggs  were  seen  in  the 
leaves  on  May  4th,  and  from  this  date 
on  the  hoppers  were  laying  eggs 
almost  continuously.  Egg  laying 
occurs  then  just  about  one  month  after  feeding  begins  on  the  vine. 
The  eggs  are  remarkably  well  tucked  away  in  the  leaf  tissues  by  means 
of  a  sharp  lance-like  ovipositor,  as  shown  in  figures  5  and  6. 


Fig.    7.     Tip     of     abdomen     of     male 
grape   leaf-hopper.      Much   enlarged. 


186 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT    STATION. 


THE    EGG. 

Description  and  Appearance. — The  eggs  of  the  grape  leaf-hopper  are 
very  minute  objects  about  three  hundredths  of  an  inch  long  and  about 
one  third  as  wide.  They  are  slightly  bean-shaped,  as  shown  in  figures 
8  and  9.  As  they  are  situated  naturally  in  the  leaf,  within  the  tissues, 
they  are  difficult  to  detect  unless  one  is  familiar  with  their  appearance. 
If  the  light  is  at  the  right  angle  the  epidermis  will  be  seen  to  be  raised 
and  slightly  more  transparent  than  the  surrounding  tissue,  and  the 
form  of  the  egg  distinguished  beneath.  We  occasionally  met  growers  who 

claimed  to  have  observed 
the  eggs  on  the  underside 
of  the  leaf ;  'but  they  were 
mistaken  in  thinking  that 
little  transparent  droplets 
of  sap  were  the  eggs  of  the 
hopper.  These  are  exuda- 
tions of  sap  which  usually 
occur  along  the  larger 
veins,  and  do  resemble 
somewhat  an  insect  egg. 
The  outer  surface  of  these 
droplets  of  sap  soon  hard- 
ens or  becomes  viscid  on 
exposure  to  the  air,  thus 
resembling  the  shell  of  an 
egg  and  making  the  simi- 
larity more  complete. 


Fig.  8.  The  egg  of  the  grape  leaf-hopper  photo- 
graphed in  its  natural  position  within  the  tissues 
of  the  leaf.  The  circular  spot  at  the  top  repre- 
sents the  eye  of  the  developing  nymph  within. 
Greatly  enlarged. 


Where  Laid,  —  Harris,1 
in  1841,  stated  that  the 
eggs  of  the  hopper  were 
laid  on  the  leaves,  but  this 
statement  appears  not  to  have  been  substantiated  by  actual  observation. 
Townsend2  in  1891  supposed  that  the  drops  of  sap,  mentioned  above, 
represented  the  egg  punctures  of  these  insects,  but  this  is  now  known 
to  be  erroneous.  Marlatt3  in  1895  stated  that  "the  eggs  are  thrust  by 
the  female  singly  into  the  substance  of  the  leaf  on  the  lower  side,  either 
into  the  midribs  and  large  veins  or  in  the  intervening  spaces."  Photo- 
graphs were  taken  of  the  eggs  in  the  leaf  in  1898  by  Professor  Wood- 
worth  of  this  station,  and  these  are  still  on  file  here.  The  first  complete 

1  Insects  Injurious  to  Vegetation,  Flint  Ed.,  p.  228. 

2  Bulletin  No.  3,  N.  M.  Agr.  Exp.  Sta. 

3  U.  S.  D.  A.  Yearbook,  1895,  p.  402. 


BULLETIN  108. 


THE   GRAPE   LEAF-HOPPER. 


187 


account  of  the  egg  and  the  first  published  pictures   were   given   by 
Slingerland1  in  1901. 

It  is  now  very  well  known  that  the  eggs  of  this  insect  are  laid  just 
beneath  the  epidermis  on  the  underside  of  the  grape  leaf.  This  is  by 
far  the  most  usual  position,  though  they  were  occasionally  found  on 
the  upper  surface.  They  are  generally  distributed  over  the  leaf  surface, 
and  occupy  no  special  position  in  relation  to  the  veins  or  ribs  of  the 
leaf.  Some  will  be  found  in  the  tissue  of  the  rib  itself,  a  good  many 
along  the  side  of  the  ribs,  and  others  scattered  about  over  the  general 
surface.  They  will  be  found  also  around  the  very  edge  of  the  leaf. 
In  thousands  of  eggs  seen  during  the  summer 
we  failed  to  find  any  arranged  in  rows  as  was 
found  by  Slingerland  in  New  York.-  The  six 
or  seven  eggs  laid  in  a  row  parallel  with  one 
another  would  represent  a  single  laying  of  a 
hopper,  and  there  is  no  reason  why  this  should 
not  be  done  occasionally,  but  it  is  not  the 
usual  occurrence  here.  We  have  found  them 
with  two  or  sometimes  three  arranged  more 
or  less  parallel,  but  never  more  than  this  num- 
ber. In  our  individual  breeding  cages,  where 
we  obtained  several  hundred  eggs,  and  where 
the  space  was  limited,  they  were  promis- 
cuously scattered  about,  one  in  a  place. 

We  confined  several  hoppers,  taken  in  pairs, 
and  liberated  these  in  cages  on  currant,  black- 
berry, loganberry  and  almond,  peach,  cherry, 
and  a  few  other  plants,  but  did  not  succeed 
in  obtaining  eggs  from  these  food  plants.  In 
most  cases  the  insects  were  found  dead  when  the  cages  were  examined 
three  or  four  weeks  later.  We  selected  the  particular  plants  named 
because  they  were  convenient,  and  not  because  the  eggs  would  be  more 
likely  to  be  laid  on  these  than  on  other  plants.  Possibly  more  nearly 
related  plants,  botanically,  would  be  found  suitable  for  oviposition. 
The  Virginia  creeper  is  said  to  be  readily  attacked  by  this  insect,3  and 
we  presume  eggs  are  laid  on  this  plant.  Since,  however,  this  species  is 
a  grape  pest  exclusively,  that  is,  during  the  growing  season,  and  all  the 
experience  indicates  that  it  feeds  only  upon  the  grapevine,  it  may  be 
stated,  so  far  as  the  economics  of  the  insect  is  concerned,  that  the  eggs 
.  are  laid  only  in  the  leaves  of  the  grape. 

1  Cornell  Agr.  Exp.  Sta.  Bull.  215. 

2  Slingerland.  Bull.  215,  Cornell  Exp.  Sta. 

3  Gillette,  Colo.  Sta.  Kept.  1000. 


Fig.  9.  The  eg§  dis- 
sected from  the  leaf 
and  photographed  on 
a  microscope  slide. 
Particles  of  leaf  tissue 
are  shown  still  ad- 
hering to  the  egg. 
Greatly  enlarged. 


188 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


Number. — The  number  of  eggs  which  are  laid  by  this  insect,  so  far 
as  we  have  been  able  to  find,  has  not  been  previously  recorded.  It 
has  been  stated  approximately  as  one  hundred,  and  this,  so  far  as  our 
experiments  went  this  year,  is  not  very  far  from  correct.  We  were  able 
to  make  individual  records  of  a  number  of  hoppers,  and  found  that  the 


Fig.  10.  Experimental  vine  used  in  the  laboratory  for  obtaining  data  on  the 
life-history  of  the  hopper.  Cages  used  for  confining  the  insects  are 
shown  on  the  leaves. 

number  laid  varied  from  forty  to  one  hundred  and  twenty-one.  These 
were  under  laboratory  conditions,  but  not  very  different  from  that  of 
the  vineyard.  The  hoppers  were  confined  in  cages  attached  to  the  grow- 
ing leaves,  as  indicated  in  figure  10. 

These  cages  were  made  by  cutting  a  square  or  rectangular  opening 
in  a  piece  of  cardboard,  on  the  underside  of  which  velvet  was  glued 
with  pile  side  outward.  This  rested  on  the  surface  of  the  leaf  and  on 


BULLETIN  198. 


THE  GRAPE  LEAF-HOPPER. 


189 


the  opposite  side;  for  the  purpose  of  holding  the  leaf  firmly  against 
the  cage,  a  piece  of  transparent  gelatine  was  used,  it  being  cut  to  cor- 
respond with  the  pasteboard  on  the  opposite  surface.  These  were 
held  together  on  the  leaf  by  means  of  ordinary  paper  clips.  Strips 
of  fairly  thick  paper  were  glued  on  the  upper  side  of  the  pasteboard, 
leaving  one  edge  free,  under  which  an  ordinary  cover  glass  could 
be  pushed.  These  cover  glasses  could  be  readily  changed  and  kept  clean, 
and  the  specimens  could  be  easily  examined,  if  necessary,  with  a  com- 
pound miscroscope.  Only  forty  eggs  were  laid  by  two  or  three  hoppers, 
but  these  probably  died  prematurely.  This  number  was  laid  in  about 
two  weeks,  which  is  a  shorter  period  than  most  hoppers  evidently  live. 
One  laid  ninety-six,  two  one  hundred  and  ten,  and  one  one  hundred 
and  twenty-one.  Since  our  observations  in  the  field  indicate  that  most 
of  the  hoppers  continue  to  lay  eggs  for  one  to  two  months,  the  number 
of  eggs  laid  will  probably  average  from  seventy-five  to  one  hundred 
and  twenty-five. 

Rate  of  Egg  Laying. — In  the  case  of  three  or  four  hoppers  we  were 
able  to  follow  pretty  closely  the  rate  at  which  the  eggs  were  deposited, 
and  the  total  length  of  the  oviposition  period.  The  following  tabulation 
for  one  of  these  is  given  below.  The  totals  are  carried  out  for  each  date  : 


Copulated  June  23d.    Case  51. 


Rate  of  Oviposition. 


Date. 

Number 
of  Eggs 
Laid. 

Date  of  Appearance  of  Nymphs. 

Hatched 
Number. 

June  30 

13 

July  10 

13 

July    2 

14 

July  17 

40 

July    3 

19 

July  18 

43 

July    6 

35 

July  19 

49 

July    7 

35 

July  20 

52 

July    9 

45 

July  22 

53 

July  16 

57 

July  23 

58 

July  17 

63 

July  24 

60 

July  19 

68 

July  26 

62 

July  22 

75 

July  27 

63* 

July  23 

75 

July  24 

79 

July  25 

79 

July  26 

79 

July  27 

79 

July  31 

85 

August   1 

85 

August  2- 

85 

August   4 

91 

August   7 

105 

August   9 

107 

August  12 

111 

August  16 

121 

August  17,  hopper  dead. 

"Total  laid  to  July  17th.    No  further  hatching  record  was  kept  for  short  intervals. 

Incubation  Period. — A  large  number  of  hoppers  wrere  liberated  on 
our  experimental  vines  at  9  A.   M.   May  29th,   and  removed  at  noon 
2— BUL.    198 


190  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

on  May  30th.  About  twenty  eggs  were  laid  on  the  vines  within  this 
period  and  the  time  for  hatching  noted.  About  half  of  these  eggs 
were  enclosed  in  individual  cages  and  an  accurate  record  kept  on  the 
whole  number.  The  first  nymph  hatched  on  June  17th  and  the  last 
June  20th,  thus  requiring  a  period  of  from  seventeen  to  twenty  days 
for  the  hatching  period. 

The  above  records  were  made  on  eggs  laid  by  the  hoppers  which  had 
remained  over  winter  and  on  the  dates  given.  There  was  a  great 
difference  however  in  the  time  required  for  hatching  of  the  eggs  from 
the  spring  brood.  The  observations  were  made  during  July  and  August 
and  included  records  on  two  or  three  hundred  eggs.  The  period 
required  for  hatching  here  was  from  eight  to  twelve  days,  all  of  the 
two  or  three  hundred  eggs  coming  within  this  limit.  We  can  account 
for  the  difference  only  in  the  higher  temperature  of  the  later  months 
or  in  the  character  of  the  eggs  from  the  two  broods.  There  was  not 
much  difference  between  the  temperature  in  June  and  July  in  the 
Lodi  section,  hardly  enough  to  account  for  all  the  difference  in  embry- 
onic development.  It  may  be  possible  that  the  vigor  of  the  adults  and 
the  increased  development  of  the  egg  when  laid  will  account  for  this 
difference  over  the  spring  brood. 

The  time  required  for  the  eggs  to  mature  in  the  ovaries  was  de- 
termined as  from  five  to  seven  days  A  number  of  pairs  in  coitu  were 
liberated  in  the  cages  and  the  first  eggs  laid  in  five  to  seven  days  later. 

Percentage  of  Eggs  that  Hatch. — The  table  indicating  rate  of  ovipo- 
sition  on  page  above  shows  that  of  the  first  sixty-three  eggs  laid  every 
one  hatched.  The  hatching  was  less  accurately  kept  for  the  remainder, 
but  we  are  quite  sure  that  every  egg  laid  by  this  particular  hopper 
brought  forth  a  nymph.  In  the  case  of  forty  eggs  laid  by  another 
hopper,  all  hatched.  With  the  layings  from  most  of  the  hoppers  in  our 
breeding  cages  a  very  high  percentage  of  the  eggs  matured.  This  was 
not  true  of  all,  however.  In  one  case  a  hopper  laid  a  total  of  thirty-five 
eggs,  scattered  along  over  a  period  of  three  weeks,  and  only  five  out 
of  the  thirty-five  hatched.  In  another  case  fourteen  eggs  were  laid  by 
an  individual  and  none  hatched.  This  experience  in  the  laboratory 
of  a  very  large  percentage  of  mortality  in  some  layings  was  also 
observed  in  the  field.  On  one  side  of  a  particular  vineyard  where 
hoppers  were  exceedingly  abundant  in  1907,  the  worst  infested  field 
seen  during  the  season,  there  was  a  very  great  mortality  in  the  egg 
stage.  On  a  single  leaf  taken  from  this  particular  area  we  have 
counted  a  total  of  seven  hundred  and  forty-seven  eggs  that  failed  to 
mature.  These  could  be  very  readily  detected  on  the  leaf  by  the  dead 
epidermis  covering  them,  which  was  dark  brown  to  black  in  color. 
The  leaf  was  thoroughly  sprinkled  with  these  black  areas,  and  showed 


BULLETIN  198.  THE  GRAPE  LEAF-HOPPER.  191 

fairly  well  in  a  photograph,  but  not  distinct  enough  to  reproduce  here. 
Upon  examining  these  eggs  that  failed  to  hatch  they  appeared  not  to 
have  started  their  course  of  development,  or  in  other  words,  were 
infertile.  The  egg  itself  was  generally  found  to  be  fresh  and  intact, 
the  black  color  on  the  leaf  being  due  in  most  cases  entirely  to  the 
epidermis  over  the  egg.  This  was  in  a  vineyard  where  the  hoppers 
appeared  in  innumerable  numbers  in  the  early  spring,  and  the  eggs  laid 
were  from  hoppers  that  had  remained  over  winter.  The  mortality  in 
the  egg  stage  reduced  their  numbers  to  a  very  appreciable  extent. 
What  was  true  of  this  one  vineyard  in  1907  was  observed  very  generally 
in  the  vineyards  around  Lodi  in  1908. 

We  tried  to  account  for  this  failure  of  the  eggs  to  mature  from  a 
number  of  causes,  but  the  matter  is  still  unsatisfactorily  settled.  We 
first  started  on  the  supposition  that  something  in  the  nature  or  make-up 
of  the  leaf,  or  a  bacterial  or  fungous  disease  of  the  egg,  might  be 
responsible.  The  underside  of  the  leaves  of  these  vines  were  covered 
over  more  or  less  with  pubescence  or  hairs.  That  this  might  have 
some  effect  in  a  mechanical  way  by  holding  moisture  and  thus  fur- 
nishing the  best  conditions  for  producing  disease  was  not  borne  out, 
since  the  same  conditions  were  noted  elsewhere  with  practically  no 
mortality.  The  hoppers  themselves  seemed  to  be  as  healthy  as  those 
elsewhere,  and  a  miscroscopical  examination  showed  nothing  unusual. 
That  the  eggs  were  infertile  seems  evident,  but  the  exact  cause  in  this 
particular  area  is  not  yet  accounted  for.  Males  were  present  in  their 
normal  numbers,  and  our  experiments  thus  far  indicate  that  they  do 
not  reproduce  parthenogetically. 

The  exact  causes  of  such  conditions  as  these  will  largely  account  for 
the  sudden  disappearance  of  the  hoppers  after  having  become  very 
abundant.  It  is  well  known  that  hoppers,  like  many  other  insects, 
have  their  ups  and  downs  as  regards  numbers.  In  1897  the  hoppers 
were  so  abundant  about  Fresno  during  the  winter  that  the  people 
appealed  to  the  University  for  aid  in  combating  them  for  the  approach- 
ing season.  An  investigation  was  undertaken  by  Professor  Woodworth 
and  headquarters  opened  for  a  season's  campaign ;  the  hoppers  appeared 
in  great  numbers  in  the  spring,  as  was  to  be  expected  from  their 
abundance  in  winter,  but  the  majority  failed  to  lay  eggs  and  none 
appeared  to  be  normally  productive,  and  as  a  result  there  were  scarcely 
enough  of  the  new  generation  produced  to  furnish  good  material  for  the 
investigation.  From  what  is  known  of  the  history  of  the  pest  in  the 
State,  this  is  an  example  of  what  occurs  more  or  less  periodically. 

Effect  of  Oviposition  on  the  Leaf. — So  far  as  we  could  see  the 
puncturing  of  the  leaf  tissues  for  egg  laying  had  no  appreciable  effect 
on  the  functions  of  the  leaf.  In  many  cases  it  was  hard  to  tell  where 


192 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT    STATION. 


an  egg  had  been  after  hatching.  In  others  the  epidermis  was  blackened. 
In  the  case  of  the  mortality  in  the  eggs,  already  referred  to,  these 
spots  were  very  numerous  ^ 

and  probably  interfered 
somewhat  with  the  normal 
functions  of  the  leaf,  but 
ordinarily  these  small  punc- 
tures have  no  noticeable 
effect  on  the  leaf. 

THE    NYMPH. 

The  young-,  immature 
hopper  is  called  a  nymph. 
It  differs  from  the  adult 
chiefly  in  the  fact  that  the 
wings  are  not  fully  de- 
veloped. These  are  grad- 
ually acquired  with  each  of 
the  five  successive  molts 
until  after  the  last  stage, 
when  the  adult  with  fully 
formed  wings  appears.  The 
stages  may  be  easily  recog- 
nized by  the  development  of 
the  wing  pads.  The  relative 
size  is  indicated  in  the  pho- 
tographs (Fig.  11),  which 
were  all  taken  under  the 
same  magnification. 

The  Hatching  Process. — 
Several  young  nymphs  were 
observed  in  the  process  of 
emerging  from  the  egg  cov- 
ering, and  it  generally  re- 
quired from  ten  to  fifteen 
minutes  for  this  process. 
After  remaining  quiet  for 
a  few  minutes  just  outside 
the  eggshell  they  would 
move  about  until  they  found 
a  suitable  '  place  for  insert- 
ing their  beaks  for  food, 
where  they  would  remain 


BULLETIN  198. 


THE  GRAPE  LEAP- HOPPER. 


193 


quiet  for  some  time.  For  a  few  days  before  the  eggs  hatch  there  is  a 
conspicuous  dark  spot  at  one  end  of  the  egg,  which  represents  the 
eye  of  the  developing  nymph  within.  It  is  at  this  end  that  the  egg 
covering  is  broken  and  the  nymph  makes  its  way  out. 

First  Stage.  —  The  young  nymph  upon  hatching  from  the  egg  is  a 
very  small  semi-transparent  whitish  creature  with  conspicuous  red  eyes. 
The  wing  pads  are  invisible.  The  head  and  thorax  appear  large  in 
proportion  to  the  abdomen,  and  the  insect  walks  in  a  more  or  less 
wabbling  manner.  The  length  of  the  period  from  hatching  to  the 
first  molt  is  four  days. 


Second  $ta(/e.—  After  the  first  molt  the  conspicuous  red  pigment  in 
the  eyes  is  partly  lost,  and  the  form  of  the  body  becomes  more  cylin- 
drical. Indications  of  yellow  markings  appear  on  the  thorax,  and  the 
wing  pads  just  begin  to  appear  as  lateral  buds.  The  length  of  this 
stage  is  two  days. 

Third  Stage.  —  The  markings  of  the  thorax  become  a  little  more 
prominent,  and  the  wing  pads  appear  as  buds  extending  posteriorly  to 
the  caudal  margin  of  the  first  segment  of  the  abdomen.  The  hind 
margin  of  the  thorax  is  curved  or  arched,  as  a  result  of  the  wing  pads 
projecting  posteriorly  at  the  sides.  The  length  of  this  stage  is  three 
days. 

Fourth  Stage.  —  There  is  not  much  change  in  the  general  appearance, 
except  that  the  wing  pads  are  now  conspicuously  larger  and  extend 
1o  the  caudal  border  of  the  second  abdominal  segment.  The  length  of 
this  stage  is  four  days. 

Fifth  and  Last  Stage.  —  The  wing  pads  now  extend  to  the  caudal 
border  of  the  third,  or  to  the  middle  of  the  fourth,  abdominal  segment. 
The  length  of  this  stage  is  five  days. 

After  the  fifth  molt  the  fully  formed  wings  appear,  extending  to 
beyond  the  tip  of  the  abdomen. 

Some  of  the  life-history  work  carried  on  to  determine  the  number 
and  length  of  the  nymphal  stages  is  indicated  in  the  following  table  : 


Cage 
No. 

Hatched  between— 

First 
Molt. 

Second 
Molt. 

Third 
Molt. 

Fourth 
Molt. 

Fifth 
Molt. 

Adult 
Stage, 
Total. 

52 

9  P.  M.  July  17  to  9  A.  M.  July  18 

7-22 

7-24 

7-26 

7-30 

8-4 

17 

53 

4  p.  M.  July  17  to  9  A.  M.  July  18 

7-22 

7-23 

7-26 

7-30 

8-4 

17 

54 

9  P.  M.  July  17  to  8  A.  M.  July  18 

7-^2 

7-24 

7-26 

7  30 

8  4 

17 

55 

4  P.  M.  July  17  to  9  A.  M.  July  18 

7-22 

7-24 

7-26 

8-1 

8  6 

19 

56 

57 

4  p.  M.  July  17  to  9  A.  M.  Julv  18  ..  _ 
4  P.  M.  July  17  to  9  A.  M.  July  18 

7-23 
7-23 

7-25 
7-25 

7-29 
7-29 

8-2 
8-2 

8-6 
8-6 

19 
19 

60a 

6  A.  M.  July  22  to  8  A.  M.  July  23 

7-2H 

7-31 

8-2 

8-5 

8-11 

19 

62 
63 

7  P.  M.  July  18  to  8  A.  M.  July  19    _ 
7  P.  M.  July  18  to  8  A.  M.  July  19^ 

7-23 
7  23 

7-24 
7-26 

7-27 
7-30 

7-30 
8-1 

8-4 
8-6 

16 

18 

194 


UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 


Cage 
No. 

Hatched  between— 

First 
Molt. 

Second 
Molt. 

Third 
Molt. 

Fourth 
Molt. 

Fifth 
Molt. 

Adult 
Stage, 
Total. 

64 

8  P.  M.  July  19  to  8  A.  M.  July  20 

7-23 

7-26 

7-30 

8-2 

8-7 

18 

65 

8  P.  M.  July  19  to  8  A.  M.  July  20 

7-23 

7-26 

7-28 

8-1 

8-6 

17 

66 

6  A.  M.  July  22  to  8  A.  M.  July  23 

7-26 

7-28 

7-31 

8-4 

8-9 

17 

66a 

6AM.  July  22  to  8  A.  M.  July  23 

7-27 

7-31 

8-1 

8-4 

8-10 

18 

67 

68 

8  P.  M.  July  19  to  8  A.  M.  July  20  
6  P   M   July  19  to  8  A   M   July  20 

7-23 
7-23 

7-26 
7-26 

7-28 
7-28 

8-1 
8  1 

8-6 
8  6 

17 
17 

70 

6  P.  M.  July  25  to  8  A.  M.  July  26 

7-30 

8-1 

8-4 

8-7 

8-13 

18 

71 

6  P.  M.  July  25  to  8  A.  M.  July  26 

7-30 

8-1 

8-4 

8-3 

8-13 

18 

69 

12  M.  July  23  to  8  A.  M.  July  24 

7-28 

7-30 

8-2 

8-5 

8-11 

18 

72 

3  P.  M.  July  26  to  8  A.  M.  July  27 

7-31 

8-2 

8-5 

8-8 

8-13 

17 

From  the  above  table  it  will  be  seen  that  the  shortest  time  required  to 
go  through  the  five  nymphal  stages  is  sixteen  days,  and  the  longest 
period  nineteen  days,  the  average  being  about  eighteen  days. 

Summarizing  the  duration  of  each  of  the  stages  as  given  above, 
it  will  be,  disregarding  fractional  days,  as  follows: 


Stage. 

Wing  Pads. 

Duration  of 
Stage. 

First 

Invisible 

4  days 

Second 

As  lateral  buds 

2  days 

Third 

Extending  to  caudal  border  first  abdominal  segment 

3  days 

Fourth 

Extending  to  caudal  border  second  abdominal  segment 

4  days 

Fifth 

Extending  to  caudal  border  third  abdominal  segment 

5  days 

Total 

18  days 

The  total  length  of  the  nymphal  life  of  the  grape  leaf-hopper  in 
New  York,  as  worked  out  by  Slingerland,1  is  from  thirty  to  thirty-three 
days.  This  is  a  difference  of  about  two  weeks  from  that  of  the  same 
species  in  California.  Climatic  conditions  probably  account  for  this 
difference,  although  so  far  as  temperature  is  concerned,  there  is  not 
much  difference  between  the  section  about  Lodi  in  June  and  July  and 
that  of  New  York  in  the  same  months. 

Molting. — As  a  preliminary  step  to  the  actual  shedding  of  the  skin, 
the  nymph  becomes  quiet  for  a  short  period,  then  the  old  skin  splits 
on  the  thorax  and  the  nymph  with  its  new  covering  makes  its  way 
out.  The  actual  working  out  from  the  old  skin  required  about  ten 
minutes,  and  in  a  very  short  time  thereafter  it  is.  able  to  move  about 
as  usual.  Immediately  after  emerging  from  the  old  skin  the  insect  is 
white  in  color  and  fairly  transparent.  The  tracheal  system  can  be 
followed  very  readily,  especially  in  the  younger  nymphal  stages,  after 
emerging  from  its  old  integument.  During  the  process  of  emerging 
the  old  skin  seems  to  be  held  on  to  the  leaf  by  the  claws  of  the  feet, 
and  these  often  remain  for  some  time  attached  to  the  leaf.  The  last 
nymphal  skin,  however,  is  much  more  firmly  attached  than  the  earlier 


Cornell  Exp.  Sta.  Bull.  No.  215,  p.  92. 


BULLETIN  198. 


THE  GRAPE  LEAP-HOPPER. 


195 


cast  skins,  and  later  in  the  season  these  last  skins  will  be  about  all  that 
will  be  seen  adhering  to  the  leaf.  The  accompanying  picture,  Fig.  12 

(and  on  the  cover  of  this  bulletin),  photographed  by  Mr.  W.  B.  Parker, 
shows  one  of  these  cast  skins  and  the  adult  which  emerged  from  it. 

Habits  of  Feeding. — The  young  nymph  upon  hatching  from  the  egg 
soon  finds  a  suitable -place  on  the  leaf  for  inserting  its  beak,  and  begins 
to  feed  on  the  plant  juices.  The  majority  of  them  remain  during  the 
earlier  nymphal  stages  on  the  same  leaf  from  which  they  originally 
emerged,  but  later  there  is  more  or  less  migration  to  other  leaves  on  the 
vine ;  but  probably 
a  large  number  re- 
main throughout 
their  nymphal  life 
on  the  same  leaf. 

Leaves  which  had 
contained  large 
numbers  of  eggs, 
some  of  which  were 
hatched  and  some 
not,  were  always 
seen  to  be  well 
stocked  with  nymphs, 
while  other  leaves 
immediately  adjoin- 
ing were  free  from 
both  eggs  and 
nymphs.  Leaves 
which  had  already 
lost  most  of  their 
green  coloring  mat- 
ter were  seen  to 

have  nymphs  in  abundance,  while  fresh  green  leaves  near  by,  offering 
a  better  food  supply,  were  observed  to  be  very  free  from  hoppers.  Of 
course,  the  nymphs  can  not  leap  or  fly,  and  so  can  not  make  their 
way  from  one  leaf  to  another  on  different  shoots  unless  they  happen 
to  be  touching,  or  else  crawl  down  to  the  base  of  the  shoot  and  up  on 
the  new  one.  Leaves  on  the  same  shoot  were  observed  to  have  a  great 
difference  in  the  number  of  hoppers,  always  being  most  abundant  on 
the  older  and  paler  colored  leaves,  where  the  most  eggs  were  to  be 
found. 

Transfer  to   Other  Food  Plants. — In   order  to   determine  whether 
nymphs  would  mature  if  transferred  to  other  food  plants  than  the 


Fig.    12.     Adult  grape  leaf-hopper  just  emerged. 


196  UNIVERSITY   OF    CALIFORNIA  -  EXPERIMENT   STATION. 

grape,  we  confined  large  numbers  of  nymphs  in  all  stages  on  apple, 
almond,  currant,  blackberry,  and  peach,  and  in  each  case  practically 
all  completed  their  development  in  due  course.  Some  of  these  were  left 
on  their  food  plants  long  enough  to  pair  and  lay  eggs,  but  we  were 
unable  to  find  any  evidence  of  eggs  having  been  deposited.  In  another 
place  it  has  been'  stated  that  adult  females  which  were  known  to  be 
fertilized  failed  to  lay  eggs  on  these  same  plants.  It  may  be  inferred 
then  that  nymphs  will  mature  on  other  food  plants,  but  it  is  at  least 
unusual,  if  ever,  that  eggs  wall  be  laid  elsewhere  than  on  the  grape. 

THE   ADULT. 

Time  of  Reaching  Maturity.  —  The  first  adults  from  the  spring  brood 
at  Lodi  w^ere  observed  on  June  8,  in  1907,  and  on  June  12,  1908,  this 
being  about  two  months  after  they  had  begun  to  feed  on  the  vine  in 
the  spring.  By  the  last  of  June  newly  emerged  adults  were  very 
common.  At  this  time  many  were  seen  pairing,  indicating  that  they 
were  fully  mature. 

Feeding  Habits.  —  The  habits  of  feeding  of  the  adults  are  not  very 
different  from  those  of  the  nymphs  except  that  they  move  about  more. 
They  wall  be  found  in  greatest  numbers  on  the  leaves  around 
the  base  of  the  vine  and  feeding  with  the  nymphs.  All 
through  the  season  the  hoppers,  in  whatever  stage  they  may 
be,  will  be  most  abundant  in  the  interior  of  the  vine.  This 
is  probably  for  protection,  since  the  food  supply  is  not  as 
good  as  that  on  the  outside  of  the  vine,  for  the  older  and 
less  succulent  leaves  are  around  the  base  of  the  vine.  So 
far  as  the  food  is  concerned  it  would  appear  that  the  newr 
Fig  13.  The  leaves  near  the  tip  of  the  growing  shoot  would  better 

adult    grape 

them,  as  is  the  case  with  plant  lice  and  some  other 


Copulation  and  Oviposition.  —  Adults  of  the  spring  brood  were  seen 
pairing  during  the  last  of  June,  and  most  commonly  about  the  middle 
of  July.  An  occasional  pair  was  seen  during  the  first  week  in  August, 
but  after  this  none  were  seen  throughout  the  rest  of  the  season. 

Egg  laying  began  with  the  spring  brood  during  the  last  week  in  June 
in  1907  and  the  same  time  in  1908.  The  overwintering  hoppers  were 
also  still  depositing  eggs,  so  that  there  appeared  an  overlapping  of 
the  two  broods. 

Activity  and  Migrations.  —  While  there  was  more  or  less  moving 
about  among  the  hoppers  in  the  same  vineyard,  no  migrations  from  one 
vineyard  to  another  were  observed  until  about  the  middle  of  July.  At 


BULLETIN  198. 


THE  GRAPE  LEAF-HOPPER. 


197 


this  time,  and  later,  hoppers  were  seen  in  some  cases  flying  about  the 
farmhouses  some  little  distance  from  any  vines.  They  were  seen  at 
night,  and  when  the  weather  was  warm  and  calm.  They  appeared  not 
to  be  going  in  any  particular  direction.  Such  migrations  or  activity 
were  only  very  occasional,  and  so  far  as  we  could  see  the  numbers  in 
the  vineyards  were  not  changed.  In  the  cases  noted  there  was  no 
particular  reason  for  the  migration  on  account  of  food.  We  believe 
that  favorable  weather  conditions  caused  greater  activity  on  the  part 
of  the  insects,  and  that  they  are  just  as  likely  to  go  back  into  the 
same  vineyard  as  to  make  a  distinct  migration  in  a  definite  direction 
for  change  of  food  or  other  reasons. 

Activity  of  the  Sexes. — Both  males  and  females  seemed  to  be  equally 
active  as  seen  from  the  proportion  of  the  sexes  taken  in  the  air 
with  a  net  when  disturbed,  and  the  fact  that  they  were  found  in  all 
situations  in  about  equal  numbers  would  seem  to  indicate  that  there 
is  no  difference  as  regards  the  activity  of  the  sexes. 

Proportion  of  the  Sexes. 


Date 

Number 
Ex- 
amined. 

Males. 

Females. 

Per  cent 
Males. 

Per  cent 
Females. 

May  20 

200 

59 

141 

29.5 

70.5 

May  20 

200 

75 

125 

37.5 

62.5 

May  22 

100 

65 

35 

65. 

35. 

May  22 

308 

150 

158 

48.7 

51.3 

May  22 

167 

89 

78 

53.2 

46.8 

June  8                                        f 

140 

75 

65 

53.5 

46.5 

June  8 

215 

85 

130 

39.5 

60.5 

Totals 

1,330 

598 

732 

45 

55 

Differences  in  Coloring  Due  to  Age. — The  hoppers  in  winter  are 
distinctly  redder  in  color,  i.  e.,  the  markings  are  more  pronounced  than 
at  any  other  season.  The  reddish  color  becomes  more  conspicuous  as 
the  winter  season  approaches,  after  they  have  left  the  vine  and  began 
to  feed  upon  their  winter  food  plants.  In  the  spring  after  they  have 
been  feeding  for  a  few  weeks  on  the  vine  they  become  distinctly  paler 
in  color  again.  This  less  conspicuous  marking  is  then  maintained 
throughout  the  life  of  the  insect  surviving  the  winter.  While  they 
have  become  distinctly  paler  in  color  after  feeding  for  two  or  three 
weeks  on  the  vine  in  the  spring,  they  are  not  so  pale  colored  as  the 
newly  hatched  hoppers,  and  the  individuals  of  the  two  broods  may 
be  distinguished  for  a  time  after  their  emergence.  The  hoppers  of  the 
second  brood  that. are  on  the  vines  in  the  fall  take  on  the  more  con- 
spicuous coloring  with  the  approach  of  the  winter  season,  and  this 
more  pronounced  marking  remains  until  after  they  have  fed  for  a 
few  weeks  on  the  vine  in  the  following  spring. 


198 


UNIVERSITY  OF   CALIFORNIA EXPERIMENT   STATION. 


The  Varieties  of  the  Species  Comes. — Altogether  there  are  nine 
varieties  of  this  species  recognized  in  the  United  States.1  All  the 
specimens  taken  on  the  grape  this  year  about  Lodi  and  Fresno,  Cali- 
fornia, were  the  typical  comes,  and  the  variety  coloradensis.  The 
difference  between  these  two  varieties  is  that  coloradensis  has  a  black 
spot  on  either  side  of  the  scutellum  at  the  base,  while  in  comes  these 


Fig.    13.     A   vine    enclosed    by    a    cheese-cloth    cage,    open    at    the    top,    for 
studying  migrations. 

spots  are  wanting.  Comes  largely  predominates,  as  is  indicated  by 
the  following  table.  The  specimens  were  mounted  on  velvet  between 
two  miscroscope  slides,  and  collected  on  the  dates  given: 

Proportion  of  the  Varieties  of  the  Grape  Leaf-hopper. 


Date. 

Slide. 

Num- 
ber. 

Comes. 

Colora- 
densis. 

1—29 

1 

150 

134 

16 

11—17- 

2 

3 

155 
145 

135 

129 

20 
16 

11-15  __ 

4 

155 

142 

13 

January—  June 

5 

136 

122 

14 

V—  25  

6 

96 

80 

16 

Total 

837 

742 

95 

Percentage.-  - 

8864 

11.35 

1  Gillette,  Proc.  U.  S.  N.  M.,  vol.  20,  1898,  p.  709. 


BULLETIN  198.  THE  GRAPE  LEAF-HOPPER.  199 

Gillette,  in  the  publication  cited,  states  that  coloradensis  is  a  very 
distinctly  marked  variety  and  one  that  seems  to  be  confined  entirely 
to  the  West.  This  does  not  mean  that  it  is  limited  to  the  Pacific  coast 
states,  for  it  occurs  commonly  in  Colorado,  and  it  is  also  found  in 
Nebraska,  Kansas,  and  New  Mexico.  Specimens  of  the  California 
varieties  were  sent  to  Professor  Gillette  and  he  replied  that  they  were 
the  typical  comes  and  coloradensis,  the  same  as  he  would  collect  on  the 
grape  in  Colorado.  So  far  as  we  know,  none  of  the  other  eight  varieties 
of  the  species  have  been  recorded  from  this  State. 

The  Common  Name  of  the  Insect. — The  insect  treated  of  in  this 
bulletin  is  probably  best  known  by  the  ^ineyardists  of  the  State  as  the 
"thrips"  or  "vine  thrips."  This  name,  however,  is  improperly  applied 
to  this  insect,  since  the  term  "thrips"  rightly  belongs  to  insects  of 
a  different  group.  The  true  thrips,  if  they  have  any  wings  at  all,  have 
delicate  fringe  wings,  and  are  not  so  active  as  the  leaf-hopper.  The 
thrips  are  very  small,  slender  bodied  insects,  ranging  from  yellowish 
to  black  in  color,  and  will  be  most  easily  found  in  flower  cups,  where 
they  feed  upon  the  sap  of  the  different  parts  of  the  flower  as  well  as 
upon  the  leaves.  There  are  several  injurious  species  of  thrips,  but  none 
do  much  damage,  so  far  as  observed,  to  the  grape.  One  particular 
species  has  become  a  very  important  pest  to  fruit  trees  in  the  Santa 
Clara  Valley.  To  avoid  confusion,  therefore,  the  term  ' '  thrips ' '  should 
be  applied  to  such  an  insect  as  this  in  the  Santa  Clara  Valley  and 
elsewhere. 

The  common  name  of  the  insect  discussed  in  this  bulletin,  as 
adopted  by  the  Association  of  Economic  Entomologists  is  the  "grape 
leaf -hopper. "  This  is  generally  shortened  in  this  State  to  simply 
"hopper"  or  "vine  hopper,"  and  this  may  be  specific  enough  here,  since, 
when  we  speak  of  "vine"  alone  there  is  no  mistaking  the  kind  of  vine 
referred  .to ;  and  it  is  generally  understood  that  all  hoppers  feed  on  the 
leaf.  However,  the  correct  common  name  of  the  insect,  as  officially 
adopted,  is  the  Grape  leaf-hopper. 

Preference  for  Different  Varieties  of  Vines. — In  many  vineyards 
infested  with  vine  hoppers  it  will  be  noticed  that  certain  varieties  of 
vines  will  be  much  worse  attacked  than  certain  other  varieties.  It 
may  be  easy,  in  the  case  of  a  single  vineyard,  to  express  in  definite 
terms  the  preference  shown  by  the  hoppers  for  particular  varieties; 
but  in  another  vineyard  in  the  same  neighborhood  these  conditions  may 
be  almost  reversed,  so  that  one  is  hardly  warranted  in  making  a  general 
statement  that  will  apply  to  all  conditions  and  all  situations. 

However,  certain  facts  were  observed  which  may  indicate  a  choice 


200  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

on  the  part  of  the  hoppers  for  particular  varieties  of  grapes.  In 
the  Lodi  section  the  two  chief  varieties  of  grapes  grown  are  the  Tokay 
and  the  Zinfandel.  Throughout  all  this  section,  so  far  as  we  observed, 
a  distinct  preference  was  shown  for  the  Tokay  over  the  Zinfandel. 
The  Mission  vines  are  also  readily  attacked  by  the  hoppers  in  this 
section.  In  a  particular  vineyard,  which  contained  these  three  varieties, 
the  Mission  and  Tokay  were  worst  infested,— the  Mission  a  little  worse 
than  the  Tokay,  while  the  Zinfandel  was  distinctly  the  least  infested. 
In  a  vineyard  at  Madera,  which  was  under  observation  for  some  time, 
the  vines  which  were  most  resistant  or  were  less  readily  attacked  by  the 
hoppers  were  the  Fehr-Yagos,  Zinfandel,  Alicante  Bouchet,  Petit 
Bouchet,  and  Mataro.  Of  these  the  Fehr-Yagos  and  Zinfandel  showed 
the  least  injury.  In  this  question  of  preference  for  varieties,  of  course 
the  difference  in  the  degree  of  susceptibility  of  the  varieties  to  an 
equal  attack  of  hoppers  must  be  taken  into  consideration;  /.  ?.,  some 
varieties  may  be  more  weakened  than  others,  although  the  hoppers  may 
be  present  in  equal  numbers.  The  actual  difference  in  the  numbers 
of  hoppers,  however,  may  be  very  readily  determined  by  jarring  the 
vines  and  observing  the  numbers  flying  about  them.  The  difference  in 
numbers  in  most  cases  is  so  great  that  there  is  little  difficulty  in  judg- 
ing this.  The  larger  numbers  of  hoppers  will  always  be  found  on 
the  vines  showing  the  most  injury  unless,  of  course,  it  is  on  those  vines 
that  are  so  badly  injured  that  most  of  the  food  supply  is  gone  and  they 
are  obliged  to  go  elsewhere  for  food. 

DEVELOPMENT. 

Length  of  Life  Cycles. — Hoppers  hatching  from  eggs  in  midsummer 
or  early  fall  remain  over  winter  and  attack  the  vine  as  soon  as  the 
foliage  appears  in  the  spring.  Here  they  feed  for  a  month,  after 
which  egg  laying  begins,  and  which  may  continue  for  two  months 
longer.  This  will  take  it  to  midsummer  again,  so  that  the  length  of 
this  life  cycle  is  approximately  one  year.  Large  numbers  of  overwinter- 
ing hoppers  were  enclosed  in  cheese-cloth  bags  in  the  vineyard,  and 
the  hoppers  were  observed  to  begin  dying  off  in  June,  and  by  the  last 
of  July  practically  all  were  dead.  Hoppers  hatching  from  eggs  laid 
in  May  and  June  begin  laying  eggs  upon  reaching  maturity  five  weeks 
later.  Egg  laying  continues  for  a  month  or  two  longer,  when  they  in 
turn  begin  to  die  off,  thus  making  the  length  of  this  life  cycle  from 
three  to  four  months. 

Number  of  Generations. — The  number  of  generations  of  the  insect 
as  indicated  above  is  two.  Although  these  broods  may  overlap  one 
another  they  are  very  distinct,  and,  at  least  in  the  Lodi  section  in  1907 


BULLETIN  198.  THE  GRAPE  LEAF-HOPPER.  201 

and  1908,  there  was  no  indication  of  a  third  brood.  There  were  two 
well  marked  periods  of  breeding,  and  none  were  seen  pairing  excepting 
during  these  periods.  For  the  overwintering  hoppers  this  period  was 
during  the  last  wreek  in  April  and  the  first  two  weeks  in  May.  For 
the  summer  brood,  or  those  hatching  from  eggs  laid  in  May  and  follow- 
ing, the  breeding  period  extended  over  the  last  week  in  June  and  the 
greater  part  of  July,  the  maximum  pairing  occurring  about  July  10th. 
The  breeding  period  of  this  brood  is  thus  seen  to  be  greater  than  that 
of  the  winter  brood  because  of  the  prolonged  hatching  period  of  the 
preceding  generation,  while  in  the  case  of  the  overwintering  hoppers 
they  all  reach  maturity  at  about  the  same  time  and  pairing  takes  place 
within  two  or  three  weeks. 

The  best  evidence  of  the  number  of  broods  is  indicated  in  the  well 
defined  periods  of  breeding,  but  this  fact  is  further  strengthened  by 
the  appearance  of  the  nymphs.  A  couple  of  weeks  after  the  maximum 
breeding  young  nymphs  appeared  in  great  abundance,  while  the 
appearance  of  the  young  gradually  diminished  as  the  time  from  these 
dates  increased.  By  September  1st  very  few  young  nymphs  were  seen, 
and  all  stages  of  nymphs  were  gradually  disappearing  and  none  at  all 
were  seen  after  October  15th.  If  there  was  even  a  partial  third  brood 
it  would  be  expected  that  young  nymphs  would  be  found  up  to  the 
time  the  leaves  fell  from  the  vine ;  but  this  would  not  necessarily  indi- 
cate a  third  brood,  for  it  might  be  due  to  the  prolonged  development  of 
the  second  brood.  The  absence  of  any  pairing  of  individuals  of  the 
second  brood  during  the  late  summer  or  fall,  and  the  young  nymphs 
ceasing  to  appear  at  the  normal  time  after  the  breeding  period  of  the 
preceding  brood,  indicate  'quite  clearly  that  there  are  two  generations 
of  the  insect  in  a  year. 

Comparison  of  Development  in  Other  Localities. — At  Fresno,  one 
hundred  and  thirty  miles  south  of  Lodi,  where  the  temperature  is  con- 
siderably higher  than  at  the  latter  place,  the  hoppers  go  through 
apparently  the  same  development,  although  the  different  stages  in 
the  life  cycles  appear  from  a  week  to  two  weeks  earlier  than  at  Lodi. 
Continuous  observation  was  not  made  on  the  hoppers  in  the  vicinity  of 
Fresno,  but  several  trips  were  made  to  this  section  during  the  season 
and  the  life  history  checked  with  that  of  Lodi,  except  that  it  was  a  week 
or  two  earlier.  In  a  visit  to  this  territory  on  October  20th  no  nymphs 
were  found  in  any  stage,  and  this  would  seem  to  indicate  that  there 
are  but  two  broods  as  at  Lodi. 


202  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

NATURAL  CONTROL. 

Climatic. — The  sudden  decrease  in  numbers  of  insects  without  any 
known  specific  cause,  a  condition  frequently  observed,  is  often  attributed 
to  the  general  and  more  or  less  indiscriminate  term  "weather  condi- 
tions." Grape  leaf -hoppers,  are  known  to  occur  in  excessive  numbers 
more  or  less  periodically,  and,  for  lack  of  definite  information,  we 
ascribe  the  cause  to  climatic  conditions.  Whether  these  conditions 
have  a  direct  effect  in  reducing  the  numbers  through  exposure,  or 
through  sudden  increase  or  decrease  of  temperature,  or  through  humid- 
ity, or  the  indirect  effect  of  these  influences  in  inducing  disease,  in 
favoring  the  development  of  parasitic  and  predatory  enemies,  in 
reducing  fecundity,  or  in  unfavorably  affecting  the 
food  supply,  are  points  not  easily  determined. 

We  have,  however,  apparently  some  evidence  on  the 
direct  effect  of  unfavorable  weather  conditions  in 
reducing  the  number  of  grape  leaf -hoppers.  During 
March,  1907,  there  were  two  or  three  weeks  of  almost 
continuous  rain.  At  the  end  of  this  period  the 
hoppers  were  found  dead  in  large  numbers  in  all  the 
vineyards  in  the  Lodi  section.  Between  seven  and 
eight  hundred  dead  hoppers  have  been  counted  under 
a  single  bunch  of  alfilaria.  In  certain  vineyards  that 


Fig  15    The  larva  of  were  flooded  with  two  or  three  feet  of  water  the 
hoppers  were  nearly  all  destroyed.     This  latter,  of 


enemy  of  the  hopper  course,   is   an   unusual    condition,    but   unfavorable 

in   California.  . 

weather   conditions   of   winter   or   early   spring   no 
doubt  destroy  large  numbers  of  these  insects. 

Parasitic.  —  The  grape  leaf-hopper  appears  to  be  particularly  free 
from  natural  enemies,  and  this  is  especially  true  of  parasitic  enemies. 
In  many  hundreds  of  eggs,  nymphs  and  adults  examined  and  kept  in 
breeding  cages  during  the  season  we  did  not  find  a  single  specimen 
parasitized. 

Predatory.  —  Most  of  the  natural  enemies  of  the  hopper  come  under 
this  category  of  predatory  or  predaceous  enemies,  but  even  this  list 
is  not  large.  The  most  common  of  these  observed  during  the  season 
was  one  of  the  aphis  lions  or  larvag  of  a  lace-wing  fly  (Fig.  15).  These 
were  present  in  most  of  the  vineyards,  and  were  frequently  seen  feed- 
ing on  the  nymphs  of  the  hoppers,  but  their  number  was  not  large 
enough  to  have  any  appreciable  effect  whatever  in  reducing  the  abund- 
ance of  the  grape  leaf-hoppers.  Ladybird  beetles  and  their  larvae 
were  also  seen  to  feed  upon  the  nymphs,  but  they  did  not  occur  in 


BULLETIN   198.  THE  GRAPE  LEAF-HOPPER.  203 

large  numbers.  Certain  spiders  which  make  their  webs  at  the  crown 
of  the  vine  seem  to  depend  for  food  very  largely  on  the  adult  hoppers 
that  are  caught  in  their  webs.  Ants  were  occasionally  seen  carrying 
away  young  nymphs  in  their  jaws.  The  ants  were  not  long  in  dis- 
covering our  supply  of  nymphs  in  the  laboratory,  which  was  on  the 
second  story  of  a  building,  and  soon  established  a  regular  line  of 
march,  where  they  could  be  seen  carrying  away  nymphs  to  their  nest 
in  the  ground  below.  A  small  red  mite  was  occasionally  found  on  the 
hoppers  at  Madera,  but  we  do  not  know  that  the  hoppers  were  actually 
killed  by  this  parasite. 

Fungous. — It  is  said  that  a  fungus  belonging  to  the  genus  Epusa 
destroyed  the  hoppers  in  Connecticut  in  1890. 1  We  saw  no  evidence 
of  fungous  disease  during  the  past  two  years.  Neither  was  there  any 
great  mortality  of  hoppers  observed,  except  in  the  egg  stage  mentioned 
in  another  place,  and  in  this  case  it  seemed  to  be  due  to  the  infertility 
of  the  eggs  rather  than  an  attack  of  fungous  disease.  Since,  however, 
these  insects  occur  in  large  numbers  and  are  closely  associated,  once 
a  fungous  disease  gets  a  foothold,  large  numbers  are  likely  to  be 
destroyed. 

MECHANICAL  CONTROL. 

Blowers  and  Suction. — On  account  of  the  habit  of  the  hoppers  of 
flying  about  in  the  vicinity  of  the  vine  when  disturbed,  it  was  thought 
that  there  might  be  a  possibility  of  drawing  them  into  a  machine  by 
means  of  suction.  A  suction  machine  was  designed  and  is  said  to 
have  worked  successfully  in  capturing  the  Rocky  Mountain  locust  in 
1874  and  1876  when  the  notable  outbreaks  of  these  insects  occurred. 
This  principle  of  suction  is  also  used  in  sawmills  for  carrying  away  the 
sawdust. 

We  started  out  on  this  problem  by  experimenting  with  a  ventilating 
fan  run  by  a  gasoline  engine.  It  was  possible  to  draw  in  good  sized 
pieces  of  paper  and  other  objects  heavier  than  small  insects,  but  the 
distance  through  which  the  suction  worked  with  sufficient  force  was 
too  short  to  be  of  any  practical  use  against  the  hoppers.  In  order  that 
such  a  machine  may  work  successfully  it  would  be  necessary  to  draw  in 
the  insects  for  a  distance  of  at  least  three  or  four  feet.  This  might 
be  accomplished  with  a  very  much  larger  fan,  but  this  would  involve 
the  use  of  heavy  machinery  that  would  be  unwieldy  for  use  in  a 
vineyard,  so  that  we  abandoned  the  idea  of  control  by  suction  as  im- 
practicable. 

With  suction  the  air  is  drawn  in  with  about  equal  force  in  all 
directions  from  the  end  of  the  tube,  so  that  there  is  not  much  force  at 

1  Thaxter,  R.,  Conn.  Sta.  Kept,  1890. 


204  UNIVERSITY   OF  CALIFORNIA EXPERIMENT   STATION. 

any  particular  point ;  but  the  air  is  blown  out  of  the  machine  in  a  very 
definite  column  and  with  much  force.  With  our  experimental  fan, 
objects  that  could  be  drawn  in  only  when  within  a  range  of  a  few 
inches,  could  be  blown  out  many  feet.  This  induced  us  to  try  blowing 
the  hoppers  into  a  funnel-shaped  receptacle.  For  this  purpose  a  large 
blacksmith's  rotary  bellows  was  used,  with  a  large  galvanized  iron 
funnel  three  or  four  feet  in  diameter  for  the  receptacle.  The  black- 
smith's bellows  did  not  produce  an  air  current  of  sufficient  diameter; 
for  this  to  work  successfully  the  diameter  of  the  current  of  air 
should  be  at  least  three  or  four  feet,  and  this  again  would  require 
bulky  machinery.  The  hoppers  also  held  on  very  tenaciously  to  the 
opposite  side  of  the  leaves  when  the  air  current  was  turned  on  them, 
and  thus  it  was  impossible  to  get  them  all  off  the  vine.  While  this 
method  of  fighting  the  hoppers  gave  more  promise  of  working  success- 
fully than  the  suction  method,  it  would  necessitate  the  use  of  rather 
expensive  and  cumbersome  machinery  that  would  not  appeal  to  the 
practical  vineyardist. 

Torches. — On  account  of  the  difficulty  of  killing  adult  hoppers  with 
any  spray  while  they  are  in  the  air,  we  tried  the  torch  as  a  means  of 
overcoming  this  difficulty.  The  torch,  which  was  tried,  consisted  of 
burning  the  kerosene  as  it  left  a/i  ordinary  spray  nozzle  which  would 
throw  a  very  fine  mist  spray.  This  was  tried  during  the  dormant 
season  on  the  hoppers  as  they  would  fly  up  from  the  vegetation  growing 
in  the  vineyards.  Even  with  this  many  hoppers  would  escape  around 
the  edges  of  the  flame,  and  this,  together  with  danger  of  scorching  the 
vine  when  in  foliage,  led  us  to  put  this  method  in  the  negative  list  of 
remedies. 

Dry  Powders. — It  has  been  very  positively  maintained  by  certain 
growers  that  they  could  kill  the  nymphs  of  the  vine  hopper  very 
successfully  by  the  use  of  air-slaked  lime.  In  order  to  determine  this 
we  made  a  number  of  experiments  by  keeping  nymphs  in  all  stages 
in  a  vial  and  thoroughly  dusting  them  and  filling  the  air  in  the  vial 
with  lime,  but  many  did  not  appear  to  be  inconvenienced  by  this 
treatment.  This  method  was  carried  out  on  a  practical  scale  by  thor- 
oughly dusting  a  row  of  vines  through  a  vineyard  by  means  of  the 
French  vermorel  machine  used  in  applying  sulfur  for  the  Oidium 
(Fig.  16).  The  air-slaked  lime  had  no  effect  whatever,  so  far  as  could 
be  observed,  on  the  number  of  nymphs. 

Pyrethrum  was  used  with  better  success  in  the  laboratory  experiments 
where  the  hoppers  were  confined,  but  the  results  in  the  vineyard  were 
not  at  all  satisfactory  in  controlling  the  nymphs.  The  expense,  more- 
over, of  pyrethrum  if  used  on  such  a  large  scale  would  be  too  great 
to  make  this  a  practical  remedy. 


BULLETIN  198. 


THE  GRAPE  LEAF-HOPPER. 


205 


The  idea  that  prevails  with  some,  that  sulfur  is  of  use  in  killing  the 
hoppers,  is  not  borne  out  by  facts.  Hoppers,  in  all  stages,  confined  in 
our  breeding  cages  in  the  vineyard,  thrived  well  in  spite  of  the  fact 
that  large  amounts  of  sulfur  were  blown  into  and  held  in  the  cages 
during  the  frequent  sulfurings  for  Oidium. 

Sticky  Shields. — Sticky  shields  have  been  used  to  some  extent  in 
fighting  the  grape  leaf-hopper,  but  a  large  number  escape  by  this 


Fig.  16.     Applying  air-slaked  lime  for  the  nymphs  of  the  hopper  by  means  of  the 
French  vermorel  machine. 

method  so  that  their  use  is  not  thoroughly  satisfactory.  A  sticky  shield 
held  on  the  leeward  side  of  the  vine  and  the  hoppers  jarred  off  will 
catch  many,  but  a  large  number  will  not  strike  the  shield.  A  three- 
sided  box  for  our  California  vines  works  best,  but  even  here  many  will 
drop  to  the  ground  or  fly  out  on  the  open  sides.  In  the  New  York 
vineyards,  two  men  each  carrying  light  sticky  shields  three  or  four 
feet  high  and  seven  or  eight  feet  long  on  opposite  sides  of  trellised 
vines,  has  been  found  to  be  a  fairly  successful  method  of  capturing 
the  hoppers.  Probably  the  best  sticky  material  for  use  on  the  shields 
in  this  State  is  the  ordinary  crude  oil. 
3— BUL.  198 


206  UNIVERSITY  OP  CALIFORNIA EXPERIMENT   STATION. 

Fumigation. — A  good  many  experiments  were  carried  on  with  a 
view  of  determining  the  feasibility  of  fumigation  as  a  means  of  con- 
trolling the  vine  hopper.  The  vines  were  enclosed  either  in  canvas 
tents,  or  a  galvanized  iron  tank  or  drum  inverted  over  the  vine,  or  a 
square  box  made  of  building  paper  (Fig.  17).  In  most  of  the  experi- 
ments carried  on  the  tank  or  box  was  used,  since  the  air  capacity  did 
not  vary  in  these  as  was  the  case  with  the  loose  canvas  tents,  and  the 
dosage  could  be  accurately  calculated. 

One  gram  of  cyanide  of  potassium  to  thirty  cubic  feet  of  space  was 


Fig.  17.     Fumigating  box  made  of  building  paper,  used  in  the  experiments  on 

fumigation. 

found  to  kill  the  hoppers  in  from  five  'to  ten  minutes.  In  some  cases' 
with  this  dose,  however,  a  few  of  the  most  tender  leaves  would  be 
slightly  burned.  The  work  was  done,  however,  during  the  day  time, 
when  the  vine  is  more  active  and  more  susceptible  to  the  gas  than 
at  night.  Because  of  the  short  exposure  necessary  to  kill  the  hoppers 
'd  few  tents  would  be  sufficient  to  keep  a  crew  of  fumigators  busy,  so 
that  the  initial  expense  of  apparatus  need  not  be  very  great.  The  dose 
necessary  for  each  vine  is  also  small,  so  that  there  is  not  a  large  expense 
of  chemicals.  The  moving  of  the  tents  from  vine  to  vine  and  the 
weighing  and  charging  of  the  chemicals,  however,  require  much  time 


BULLETIN  198. 


THE  GRAPE  LEAF-HOPPER. 


207 


and  labor.  The  accurate  weighing  of  such  small  quantities  of  cyanide 
and  the  liability  of  injuring  the  vine  or  not  killing  the  insects,  if  this 
is  not  carefully  done,  make  the  method  too  complicated  for  the 
practical  vineyardists,  besides  being  more  expensive  than  other  methods 
of  control  discussed  farther  on. 

Some  experiments  were  tried  by  a  vineyardist  near  Lodi  with  burning 
sulfur  and  liberating  the  gas  in  a  drum  enclosing  the  vine,  as  shown  in 
figure  18.  A  fire  was  made  in  a  small  cylinder  on  the  side  of  the  drum 
and  sulfur  blown  over  this  by  means  of  an  ordinary  sulfur  bellows, 


Fig.  18.  An  apparatus  for  fumigating  with  the  fumes  of  sulfur,  designed 
by  a  vineyardist  at  Lodi.  The  tent  in  the  background  is  for  hydro- 
cyanic acid  gas. 

thus  converting  the  sulfur  into  a  gas  which  was  conducted  through  a 
tube  entering  the  drum  near  the  bottom.  It  was  diificult  to  regulate 
the  amount  of  gas  with  this  apparatus,  so  that  the  vines  generally  were 
badly  scorched.  Some  modification  of  this  apparatus  might  be  made 
to  work  successfully;  but  sulfur  fumes  S02,  at  least  when  used  alone, 
is  not,  apparently,  a  good  insecticide,  and  on  the  other  hand,  plants  are 
very  susceptible  to  injury  ^by  this  gas.  There  is,  therefore,  a  very 
small  margin,  if  any,  between  a  dose  that  will  kill  the  insects  and  not 
injure  the  plant.  A  grower  at  Madera  thought  he  could  kill  the 
hoppers  by  burning  sulfur  between  the  vines.  A  handful  or  two  of 


208  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT   STATION. 

sulfur  on  a  piece  of  burlap  sacking  was  placed  between  every  four 
vines  over  about  one  quarter  of  an  acre,  and  the  sulfur  burned.  The 
hoppers  apparently  suffered  no  discomfiture,  but  the  foliage  on  the 
windward  side  of  the  vines  was  badly  burned. 

Sprays  and  Washes. — Various  kinds  of  sprays  and  washes  were 
tried  'for  killing  the  adult  hoppers  in  the  spring,  and  also  during  the 
winter  while  they  were  still  on  their  winter  food-plants.  None  of 
these  were  successful  because  of  the  activity  of  the  hoppers,  for  it  was 
impossible  to  drench  those  in  the  air  thoroughly  enough  to  kill  them. 


Fig.  19.     Spraying  for  the  nymphs. 

Pure  kerosene  was  used  while  they  were  still  on  the  vegetation  in 
winter,  and  even  with  this  strong  material  probably  the  larger  per  cent 
escaped  on  account  of  their  activity.  They  could,  however,  be  quite 
readily  killed  if  they  were  against  something,  as  the  ground  or  a  leaf, 
where  the  spray  would  wet  them  thoroughly. 

Spraying  for  the  nymphs,  however,  is  a  different  problem,  and  it 
is  practical  to  get  a  very  large  per  cent  of  them  by  this  method.  The 
nymphs  are  all  on  the  underside  of  the  leaves  and  they  are  not  capable 
of  flying  or  jumping,  so  that  it  is  possible  to  hit  them  with  a  spray. 
The  sprays  which  gave  the  best  results  were  the  whale  oil  soap  solution 
and  the  resin  spray, — the  soap  solution  being  probably  a  little  the  better. 


BULLETIN  198. 


THE  GRAPE  LEAF-HOPPER. 


209 


One  pound  of  soap  was  used  to  fifteen  gallons  of  water.  In  the  case 
of  the  resin  one  pound  was  used  with  fifteen  gallons  of  water  and  enough 
lye  or  potash  to  completely  dissolve  the  resin.  This  is  at  the  rate  of 
one  pound  of  lye  to  about  eight  pounds  of  resin. 

The  time  to  spray  for  the  nymphs  is  when  they  first  reach  their 
maximum  numbers  in  the  spring,  just  before  the  first  of  them  change 
into  the  adult  winged  hoppers.  This  was  during  the  last  of  May  and 
the  first  of  June  during  the  past  two  years  at  Lodi. 

The  spray  should  be  applied  from  below  and  the  under  side  of 
every  leaf  thoroughly  wetted  with  the  solution,  since  the  spray  will 
kill  no  more  nymphs  than  it  hits.  This  is  not  very  difficult  to  do  in 


Fig.  20.  An  apparatus  designed  by  a  vineyardist  at  Madera  for  use  against 
both  the  leaf-hopper  and  grasshoppers.  The  trough  at  the  bottom  con- 
tains crude  oil,  into  which  the  hoppers  are  supposed  to  fall  upon  hitting 
the  upright  screen. 

May  or  early  June,  while  the  shoots  are  still  comparatively  short.  The 
best  type  of  nozzle  to  use  is  the  cyclone,  with  the  spray  emerging  at 
right  angles  with  the  long  axis  of  the  rod,  shown  in  figure  19.  This 
will  allow  the  operator  to  poke  the  rod  anywhere  among  the  vines  with- 
out its  being  caught. 

The  spray  is  intended  to  kill  the  nymphs  only.  There  are  adults 
always  present  which  will  escape,  and  the  spray  will  not  prevent  what- 
ever eggs  may  be  present  from  hatching  later.  In  bad  cases  of  vine 
hopper  injury,  however,  it  will  pay  well  to  do  this  spraying  for  the 
nymphs,  if  the  screen  method,  described  below,  has  not  been  used  or 
the  work  not  effectually  done. 


210 


UNIVERSITY   OF  CALIFORNIA — EXPERIMENT   STATION. 


Screens  or  Cages. — In  our  work  of  spraying  for  the  adults  it  was 
soon  determined  that,  if  a  spray  was  to  be  used  successfully,  the 
active  hoppers  must  be  confined  within  certain  limits  in  order  to  give 
time  to  hit  them  thoroughly  with  the  spray.  The  screen  cage  shown  in 
Fig.  21  was  developed  as  a  result  of  this,  it  being  intended  to  apply 
the  spray  from  the  open  side  through  a  hole  in  a  canvas  curtain  which 
could  be  dropped  down  as  the  cage  was  pushed  onto  the  vine.  This 


Fig.  21.     A  screen  cage  used  to  capture  the  grape  leaf-hopper. 

was  found  to  work  quite  satisfactorily.  It  was  noticed,  however, 
that  when  the  base  of  the  V-shaped  opening  on  the  bottom  of  the  cage 
struck  the  vine  most  of  the  hoppers  were  jarred  off.  This  suggested  the 
use  of  a  sticky  material  on  the  sides  and  bottom  of  the  cage  and  jarring 
them  on  to  this,  and  thus  dispensing  with  the  spray. 

This  method  of  capturing  the  adult  hoppers  by  means  of  the  screen 
cage  in  the  early  spring  proved  to  be  the  most  successful  of  all  the 
means  of  control  tried  during  the  season. 

The  screen   cage  is  made  by  tacking   a   double   layer   of   ordinary 


BULLETIN  198. 


THE  GRAPE  LEAF-HOPPER. 


211 


galvanized  mosquito  wire-netting  over  a  square  frame  of  wood  or 
laths  or  other  light  material.  A  single  covering  of  mosquito  netting 
will  allow  some  hoppers  to  escape  through  the  mesh.  If  it  is  obtainable, 
a  20-mesh  screen  would  be  preferable.  Ordinary  galvanized  mos- 
quito wire-netting,  however,  can  be  obtained  almost  anywhere,  and 
two  layers  of  it  work  very  satisfactorily.  The  bottom  of  the  cage 
consists  of  a  shallow  tray.  This  is  made  by  turning  up  about  an  inch 
or  an  inch  and  a  half  of  the  edges  of  a  sheet  of  light  galvanized  iron. 
There  are  two  grades  of  this  iron,  and  the  heavier  grade  adds  much 
more  weight  than 
is  necessary.  One 
side  of  the  box  is 
kept  open  and  there 
is  a  V-shaped  open- 
ing (Fig.  22)  in  the 
tray  at  the  bottom 
which  permits  the 
cage  to  be  pushed 
on  to  the  vine.  At 
the  same  time  that 
the  cage  is  swung 
into  position  the  vine 
is  bumped  by  the 
base  of  the  opening, 
which  is  padded 
with  leather,  thus 
jarring  the  hoppers 
off.  The  sides  and 
bottom  of  the  cage, 
having  been  pre- 
viously smeared 
with  crude  oil,  catch 
all  the  hoppers  that 

fall  on  to  them.  The  cage  should  be  operated  with  the  open  side  facing 
the  direction  from  which  the  wind  is  blowing.  If  there  is  a  breeze 
blowing,  very  few  will  escape  on  the  open  side.  However,  if  there  is 
no  breeze,  and  the  hoppers  are  especially  active,  a  canvas  curtain 
fastened  on  the  front  of  the  cage  at  the  top  can  be  very  readily  dropped 
down  as  the  cage  comes  into  position,  thus  shutting  off  all  possibility 
of  escape. 

The  bottom  of  the  cage  is  a  very  essential  feature,  since  most  of  the 
hoppers  drop  to  the  bottom  at  the  back  of  the  cage  or  are  caught  within 
a  foot  or  two  from  the  bottom  on  the  sides.  To  prevent  any  escaping 
by  dropping  down  through  the  opening  in  front  of  the  vine  this  may 


Fig.    22. 


The  hopper  cage  with  the  V-shaped  opening  at 
the    bottom    covered    with    canvas. 


212  UNIVERSITY  OF  CALIFORNIA EXPERIMENT   STATION. 

be  covered  with  canvas  as  shown  in  figure  22.  Two  pieces  of  canvas 
meeting  in  the  center  are  tacked  on  the  sides  of  the  opening.  Pieces 
of  rubber  tubing  extending  transversely  are  sewed  on  the  canvas  and 
their  ends  securely  tacked  down  at  the  sides,  leaving  them  otherwise 
free,  excepting  as  they  are  fastened  in  the  canvas.  As  the  cage  is 
pushed  on  to  the  vine  the  canvas  and  the  free  ends  of  the  rubber  give 


Fig.  23.  A  photograph  of  the  interior  of  the  cage  shown  in  Fig.  21,  after 
15  minutes  use  where  hoppers  were  very  abundant.  The  white  specks  at 
the  back  each  represents  a  hopper,  stuck  in  the  oil  with  which  the  screen 
has  been  smeared.  A  portion  of  the  tray  at  the  bottom,  which  is  outside 
the  shadow  on  the  left,  shows  a  solid  surface  of  hoppers. 

way,  but  immediately  spring  back  into  position  again  on  account  of 
the  flexibility  of  the  rubber  tubing.  This  canvas  may  be  covered  with 
oil,  and  thus  the  bottom  is  completely  covered. 

The  advantage  of  the  screen  is  that  it  does  not  shut  off  the  light 
and  also  allows  the  wind  to  blow  through  so  that  the  great  majority  of 
the  hoppers  will  go  downward  and  toward  the  leeward  side  of  the  vine. 
A  cage  built  of  canvas  was  tried,  but  proved  unsuccessful  because 


BULLETIN  198.  THE  GRAPE  LEAP-HOPPER.  213 

most  of  the  hoppers  came  out  on  the  open  side  toward  the  light,  and 
it  was  with  difficulty  that  they  could  be  caught  on  the  black  oiled 
canvas.  The  canvas  also  absorbs  more  of  the  oil  than  the  screen  and 
makes  a  drier  surface  for  the  hoppers  to  light  upon,  thus  failing  to 
hold  them  as  well  as  the  free  oil  on  the  wire  of  the  screen. 

Kerosene  may  be  used  on  the  screen  as  well  as  crude  oil,  but  it 
evaporates  more  rapidly  and  more  frequent  applications  are  necessary. 
For  a  fine  mesh  screen,  however,  the  kerosene  works  very  well,  since 
it  does  not  darken  the  sides  so  much  as  the  black  crude  oil. 

The  time  to  use  this  screen  cage  is  in  the  early  spring  when  the 
shoots  of  the  vine  are  not  more  than  four  or  five  inches  long.  At  this 
time  all  the  hoppers  have  left  their  winter  food  plants  and  have  begun 
to  feed  upon  the  vines,  and  none  have  yet  laid  eggs.  This  method, 
therefore,  captures  them  at  a  critical  time  before  they  have  begun  to 
breed,  and  thus  greatly  reduces  the  numbers  of  the  succeeding  gen- 
erations. 

The  work  may  also  be  done  more  easily  and  effectively  at  this  time, 
since  there  is  not  the  excessive  foliage  that  appears  as  the  season 
advances.  The  size  of  the  vines  to  be  treated  will  determine  the  size 
of  the  cage.  Ordinarily,  the  cage  need  be  but  very  little  larger  than 
the  diameter  of  the  vines  after  pruning.  In -one  young  vineyard,  two 
years  old,  the  hoppers  were  kept  down  successfully  by  a  small  cage 
about  one  foot  square,  which  was  easily  handled  by  one  man.  With  the 
larger  cages  three  feet  square,  handles  are  attached  to  each  side  and 
the  cage  manipulated  by  two  men.  One  of  these  cages  with  two  men 
will  go  over  four  or  five  acres  a  day.  There  is  practically  no  expense 
for  materials  and  the  time  of  the  men  is  the  chief  outlay. 

If  this  screen  cage  is  conscientiously  used  it  will  capture  from  85% 
to  95%  of  the  hoppers,  and  at  a  time  in  the  life-history  of  the  insect 
when  for  each  hopper  taken  it  means  a  hundred  or  so  less  later  in  the 
summer. 

This  method  of  capturing  the  hoppers  with  the  screen  cage  was 
developed  for  vines  that  are  headed  some  little  distance  above  the 
surface  of  the  ground.  There  are  many  vineyards  in  the  State,  however, 
that  have  not  been  so  pruned.  Some  are  headed  directly  at  the  surface, 
and  in  some  even  the  canes  come  out  from  the  stump  beneath  the 
surface,  and  a  cone-shaped  area  is  scooped  away  to  make  room  for  the 
growth  of  the  canes.  This  form,  in  some  cases,  is  given  to  the  vine 
by  frost;  but  where  the  pruning  is  responsible,  it  is  generally  considered 
now  to  be  a  bad  system. 

If  the  cage  is  to  be  used  on  such  vines,  it  must  be  done  with  some 
modification  of  the  bottom  or  the  bottom  dispensed  with  entirely,  though 
this  is  an  important  part  of  the  apparatus. 


214  UNIVERSITY  OF  CALIFORNIA — -EXPERIMENT  STATION. 

In  the  case  of  staked  vines  it  is  possible  to  work  this  cage  if  the 
top  is  left  off,  or  enough  of  the  top  so  as  not  to  interfere  with  the 
stake.  An  opening  may  be  left  in  the  top  similar  to  the  V-shaped 
opening  at  the  bottom.  A  staked  vineyard  was  gone  over  with  this 
modified  cage  and  practically  no  hoppers  escaped  through  the  opening 
at  the  top.  Such  an  apparatus  can  not  be  used  at  all,  of  course,  on 
trellised  vines.  For  trellised  vines  we  would  suggest  the  use  of  sticky 
shields  as  are  used  in  New  York  vineyards,  excepting  that  the  canvas 
be  replaced  by  wire  screen  netting.  These  should  be  three  or  four  feet 
high  and  seven  or  eight  feet  long,  and  two  of  them  operated  together 
on  opposite  sides  of  the  trellis. 

FARM  PRACTICES. 

Plowing. — Plowing  is  sometimes  done  by  California  vineyardists 
during  the  winter  season  for  the  purpose  of  destroying  the  grape  leaf- 
hoppers.  This  is  partly  based  upon  the  supposition  that  the  eggs 
may  be  in  the  leaves  or  in  the  ground,  or  that  the  adult  hoppers  are 
in  some  way  killed  in  the  operation.  So  far  as  having  a  direct  effect 
in  destroying  the  hoppers  is  concerned,  plowing  is  of  little  avail.  The 
only  ones  that  will  be  killed  are  a  few  that  may  not  be  disturbed  from 
their  resting  places  among  the  leaves,  or  otherwise  accidentally  buried 
by  the  plow.  During  the  cold  or  rainy  days  there  may  be  a  few  thus 
turned  under,  but  ordinarily  they  are  active  enough  to  escape  readily 
before  the  plow. 

Plowing,  however,  may  have  an  indirect  effect  on  the  hoppers  by 
depriving  them  of  food,  or  of  suitable  sheltering  places  during  un- 
favorable weather  conditions,  and  if  this  practice  is  generally  carried 
out  in  a  neighborhood  it  will  no  doubt  result  in  reducing  the  numbers 
somewhat.  However,  a  field  may  be  free  from  hoppers  during  the 
winter,  but  this  is  not  necessarily  an  indication  of  freedom  from  spring 
infestation.  The  insects  are  more  generally  distributed  in  the  winter 
season,  but  the  bulk  of  them  will  usually  be  found  in  the  vineyard,  or 
on  the  vegetation  of  the  borders  immediately  surrounding  it.  They 
may  come  in,  therefore,  from  vineyards  closely  adjoining,  so  that 
plowing  a  single  vineyard  may  be  of  little  help.  When  the  plowing  is 
done  in  a  single  vineyard  or  over  a  small  area  it  is  likely  to  result 
simply  in  driving  them  into  other  fields,  where  there  is  a  better  food 
supply.  Once  in  these  other  situations  they  may,  or  may  not,  come 
back  into  the  vineyard  where  they  were  originally. 

Sheeping. — Some  growers  turn  sheep  into  the  vineyard  soon  after 
the  crop  is  harvested  and  allow  them  to  eat  off  the  leaves  of  the  vines. 
This  should  not  be  done  until  the  leaves  have  completed  their  growth 


BULLETIN  198.  THE  GRAPE  LEAP-HOPPER.  215 

and  are  about  ready  to  fall  naturally.  The  chief  result  of  this  practice 
is  to  drive  the  hoppers  elsewhere  for  food.  In  the  late  fall  the  adult 
hoppers  are  still  feeding  on  the  vine  foliage,  and  there  they  continue  to 
feed  until  the  leaves  lose  their  succulent  material  and  dry  up.  When 
sheep  are  turned  in  among  the  vines  and  the  foliage  eaten  off,  the 
hoppers  will  either  go  to  an  adjoining  vineyard  that  is  still  in  foliage, 
or  simply  begin  to  feed  a  little  earlier  on  their  wide  range  of  winter 
food  plants  which  may  be  growing  in  the  vineyard  or  vicinity.  The 
destruction  of  the  leaves,  however,  does  away  with  the  sheltering  places 
that  would  be  formed  by  the  leaves  accumulating  in  bunches  by  the 
wind ;  and  a  clean  vineyard  is  always  freer  from  hoppers  in  the  winter 
season  than  one  where  there  is  an  abundance  of  leaves  or  of  growing 
vegetation.  But  there  is  nothing  to  protect  such  a  vineyard  from  a 
possible  infestation  in  the  spring  from  the  adjoining  vineyards. 

Plowing  and  sheeping,  then,  result  chiefly  in  partially  destroying  the 
food  supply  over  a  limited  area,  and  of  doing  away  with  possible 
hibernating  places  in  the  bunches  of  leaves  that  would  otherwise 
accumulate.  The  usefulness  of  such  practices  will  depend  largely  on 
how  generally  they  are  carried  out  in  a  neighborhood,  and  at  best  can 
be  counted  on  simply  to  reduce  the  number  of  hoppers,  which,  generally, 
is  not  likely  to  be  at  a  point  of  effective  control. 


SUMMARY. 

The  grape  leaf-hopper  is  one  of  the  most  important  insect  pests  of 
the  vine  in  California,  as  may  be  seen  by  the  most  casual  observer  in 
the  large  amount  of  foliage  that  dries  up  prematurely  on  the  vines  in 
many  sections  of  the  State  each  year. 

Life  History. — The  hoppers  pass  the  winter  as  adult  insects  on  a  wide 
range  of  food  plants  that  may  be  growing  in  the  vineyard  or  vicinity. 

They  attack  the  vine  as  soon  as  the  foliage  appears,  and  here  they 
remain  until  the  leaves  fall  in  the  autumn. 

One  month  after  they  begin  feeding  on  the  vine,  the  overwintering 
hoppers  begin  egg  laying,  which  is  continued  over  a  period  of  a  month 
or  two,  after  which  they  die.  The  hoppers  of  the  spring  brood  arising 
from  eggs  laid  in  May,  become  full  grown  in  three  weeks,  begin  egg 
laying  two  or  three  weeks  later,  and  die  off  in  August  or  September, 
making  the  life  of  this  spring  brood  approximately  three  or  four  months. 
Hoppers  arising  from  eggs  laid  by  the  spring  brood  in  June  and  later, 
remain  on  the  vine  until  the  leaves  fall  in  autumn.  They  then  take  to 
whatever  succulent  vegetation  may  be  present  in  the  neighborhood, 
where  they  live  over  winter  and  attack  the  vines  again  in  the  following 


216  UNIVERSITY  OP  CALIFORNIA — EXPERIMENT  STATION. 

spring.  These  begin  depositing  eggs  a  month  after  the  leaves  appear 
on  the  vine,  and  die  off  in  midsummer,  making  the  length  of  this  life 
cycle  approximately  one  year  in  the  central  valleys  of  California. 

Control. — The  most  satisfactory  control  method  tried  during  the  past 
two  years  was  the  use  of  the  screen  cage.  This  was  found  to  capture 
about  85%  to  95%  of  the  adult  hoppers  at  a  time  in  the  spring  before 
any  eggs  are  deposited. 

Spraying  for  the  nymphs  about  June  1st,  or  just  before  the  spring 
brood  becomes  mature,  will  kill  a  satisfactory  percentage  of  the  nymphs 
or  young,  but  will  not  kill  many  adults,  or  prevent  eggs,  which  are 
present  at  this  time,  from  hatching  later.  If  the  cage  method  has  not 
been  used,  or  satisfactorily  operated,  spraying  for  the  nymphs  will  very 
materially  aid  in  reducing  the  numbers  of  the  spring  generation. 

Plowing  or  other  farm  practices  can  not  be  relied  upon,  but  when 
such  measures  are  generally  practiced  throughout  a  neighborhood,  they 
may  aid  in  reducing  the  numbers  somewhat. 


LITERATURE.  217 


LITERATURE. 

1825.  Say,  Thomas.     Jour.  Acad.  Nat.  Sci..  Phil.,  iv,  327. 

1828.  Fessenden.     New  Am.  Gard.,  Bost,  299. 

1831.  Harris,  T.  W.     Encycl.  Amer.,  viii,  43. 

1841.  Harris,  T.  W.     Insects  Inj.  to  Veg.,  Flint  Ed.,  22S. 

1843.  Allen,  Pract.  Treatise  on  the  Grape  Vine,  132. 

1848.  Downing's   Horticulturist,   iii,   28. 

1854.  Glover,  Towend.     Rpt.  U.  S.  AST.,  77-78. 

1856.  Fitch,  A.    3rd  Rpt.  on  Insects  of  N.  Y.,  391. 

1861-2.  Fitch,  A.     7th  Rpt.  on  Insects  of  N.  Y. 

1864.  Walsh,  B.  D.     Proc.  Boston  Soc.   Nat.  Hist,  ix,  317-318. 

1867.  Walsh,  B.  D.  Pract.  Ent.,  ii,  49-52. 

1868.  Bethune,  C.  J.  S.    Can.  Farmer,  v,  113-114. 

1868.  Kirkpatrick,  J.     Ohio  Farm.,  iii,  3. 

1869.  Walsh,  B.  D.  and  Riley,  C.  V.     Am.  Ent,  i,  227. 

1870.  Saunders,  W.     Rpt.  Fruit  Grow.  Assoc.,  Ont,  94-117. 

1871.  Glover,  T.    Monthly  Rpt.  U.  S.  D.  A.,  Nov.  and  Dec.,  477-480. 
1871.  Saunders,  W.     Rpt.  Ent  Soc.,  Ont,  17-21. 

1871.  Glover,  T.     Rpt.  U.  S.  Com.  Agr.,  69-88. 

1873.  Riley,  C.  V.     Trans.  111.  St.  Hort.  Soc.,  vii.  138. 

1875.  Packard,  A.   S.     Rpt.  U.   S.   Geol.   Sur.,  1875-77-78. 

1875.  Cook,  A.  J.     13th  Ann.  Rpt  St.  Bd.  Agr.,  Mich. 

1876.  Glover,  T.     Rpt  U.  S.  D.  A.,  p.  32. 

1877.  Packard,  A.  S.     Am.  Nat.,  ii,  786. 

1878.  Perkins,  G.  H.     5th  Rpt  Ver.  Bd.  Agr.,  250-286. 
1880.  Riley,  C.  V.     Amer.  Ent,  i,  182. 

1883.  Devereaux,  W.  L.     Rural  New  Yorker,  vol.  47,  p.  474. 

1883.  Saunders,  W.     Ins.  Inj.  to  Fruits,  286. 

1884.  Uhler,  P.     Stand.  Nat.  Hist,  ii,  246. 

1885.  Lintner,  J.  A.    33d  Ann.  Rpt  Mass.  Bd.  Agr.,  165-196. 

1887.  Lintner,  J.  A.     Cult  and  Count.  Gent,  Hi,  493. 

1888.  Lintner,  J.  A.     Vineyardist,  ii.  113. 

1888.  Fernald,  C.  H.     Mass.  Hatch.  Exp.  Sta.  Bull.  2,  p.  3. 

1888.  Bethune,  C.  J.  S.     19th  Ann.  Rpt  Ent.  Soc..  Ont,  63-74. 

1888.  Marvin,  D.   S.     Rural  New  Yorker,   Sept  576. 

1889.  Woodworth.  C.  W.     Psyche,  v.  213. 

1889.  Fernald,  C.  H.     Orange  Judd.  Farm.,  xviii,  May. 

1889.  Fernald,  C.  H.     Mass.  Hatch.  Exp.  Sta.  Rpt,  p.  21. 

1890.  Provancher.     Pet  Fauna  Ent.  Can.,  iii,  298. 
1890.  Cassidy,  J.     Bull.  6,  Colo.  Exp.  Sta. 

1890.  Thaxter,   R.     Conn.   Sta.   Ann.   Rpt..   95-98. 

1890.  Blount,  A.  E.     Bull.  2,  N.  M.  Exp.  Sta.,  378-386. 

1890.  Gravestock,  J.     Proc.  Colo.   Sta.  Hort.   and  Forest  Assoc. 

1891.  Gillette,  C.   P.     Bull.  15,  Colo.  Agr.   Exp.   Sta.   18. 
1891.  Fletcher,  J.     Can.  Cent  Exp.  Farm.  Bull.,  xi,  May. 
1891.  Townsend,  C.  H.  T.     N.  M.  Exp.  Sta.  Bull.,  iii. 
1891.  Weed,  C.  M.     Ann.  Rpt.  Columbus  Hort.  Soc.,  166. 
1891.  Cockerell,  T.  D.  A.     N.  M.  Agr.  Exp.  Sta.  Rpt  114. 

1891.  Lintner,  J.   A.     Country  Gentlemen,  Oct.,  815. 

1892.  Weed,  C.  M.     Insects  and  Insecticides. 
1892.  Townsend,  C.  H.  T.     N.  Mex.  Sta.  Bull.  5. 

1892.  Gillette,  C.  P.     Colo.  St.  Bd.  Hort..  230. 

1893.  Osborn,  H.    Trans.  Iowa  St.  Hort.  Soc.,  262-264. 
1893.  Fletcher,  J.     Rpt  Exp.   Farms.   Can.,   157-193. 

1893.  Fitch,  A.     Reprint  Lintner's  9th  Rpt.   Ins.   N.   Y..  403. 

1893.  Webster,  F.  M.     Ann.  Rpt.  Ohio  St.  Hort  Soc.  63-76. 

1894.  Van  Duzee,  E.  P.     Trans.  Am.  Ent.  Soc.,  xxi,  312. 

1894.  Gravestock,  J.     Proc.  Colo.  St.  Hort  Assoc.,  229-233. 

1895.  Gillette,  C.  P.     Colo.  Sta.  Bull.  15. 

1895.  Marlatt,  C.  L.     U.  S.  D.  A.  Yearbook,  385-404. 

1895.  Gillette,  C.  P.  and  Baker,  C.  F.     Colo.  Exp.  Sta.  Bull.  31,  p.  113. 

1895.  Comstock,  J.   H.     Manual  of  Insects,  154. 

1895.  Webster,  F.  M.    Ohio  Farm.,  Nov.  373. 
*1896.  Lugger,  O.     Minn.  Sta.  Bull.,  48. 
*1896.  Marlatt,  C.  L.     Am.  Nat.  Sept  759. 

1896.  Slingerland.  M.  V.     Rural  New  Yorker,  17th  Oct.,  689. 

1896.  Smith,  J.  B.     Economic  Entom.,  148. 

1897.  Woodworth,  C.   W.     Cal.   Sta.   Bull.,   116. 
1897-8.  Clarke,  W.  T.    Ann.  Rpt  Cal.  Sta. 

1900.  Gillette,  C.  P.     Ann.   Rpt.   Colo.  Sta. 


218  LITERATURE STATION  PUBLICATIONS 

1901.  Felt,  E.  P.     Bull.  N.  Y.  St.  Mus.,  53. 

1901.  Slingerland,  M.  V.      Cornell  Exp.   Sta.  Bull.  215. 

1902.  Felt,  E.  P.     Proc.  14th  Ann.  Meet.  A.  E.  E.,  Bull.  37,  U.  S.  D.  A. 

1903.  Slingerland,  M.  V.     Rpt.  1903  Meet.  A.  A.  A.  S. 

1903.  Okla.  Sta.  Rpt.,  pp.  15-71. 

1904.  Smith,  J.  B.     N.  J.  Sta.  Rpt.  557-652. 

1907.  Quaintance,  A.  L.     Farm.  Bull.  284,  U.  S.  D.  A. 

1907.  Woodworth,  C.  W.     Insects  of  Cal.,  44. 

1908.  Quayle,  H.  J.     Jour.  EC.  Ent,  v.  3,  no.  1. 


STATION  PUBLICATIONS  AVAILABLE  FOR  DISTRIBUTION. 


REPORTS. 

1896.  Report   of   the   Viticulrural    Work   during    the   seasons    1887-93,    with    data 

regarding  the  Vintages  of  1894-95. 

1897.  Resistant   Vines,    their    Selection,    Adaptation,    and    Grafting.      Appendix    to 

Viticultural   Report   for   1896. 

1898.  Partial   Report  of  Work  of  Agricultural   Experiment  Station  for  the  yearr 

1895-96  and  189(5-97. 
1900.     Report  of  the  Agricultural  Experiment  Station  for  the  year  1897-98. 

1902.  Report  of  the  Agricultural  Experiment  Station  for  1898-1901. 

1903.  Report  of  the  Agricultural  Experiment  Station  for  1901-1903. 

1904.  Twenty-second  Report  of  the  Agricultural  Experiment  Station  for  1903-1904. 

TECHNICAL  BULLETINS— ENTOMOLOGICAL  SERIES. 

Vol.  1,  No.  1 — Wing  Veins  of  Insects. 

No.  2 — Catalogue  of  the  Ephydridse. 

BULLETINS. 

Reprint.     Endurance  of  Drought  in  Soils  of  the  Arid  Region. 

No.  128.     Nature,  Value  and  Utilization  of  Alkali  Lands,  and  Tolerance  of  Alkali. 
(Revised  and  Ueprint,  1905.) 

133.     Tolerance  of  Alkali  by  Various  Cultures. 

140.     Lands  of  the  Colorado  Delta  in  Salton  Basin,  and  Supplement. 


142.     Grasshoppers  in  California. 
147.     Culture  Wo 


'ork  of  the  Substations. 

149.  California   Sugar   Industry. 

150.  The  Value  of  Oak  Leaves  for  Forage. 

151.  Arsenical  Insecticides. 

152.  Fumigation  Dosage. 

153.  Spraying  with  Distillates. 
354.  Sulfur  Sprays  for  Red  Spider. 
15(5.  Fowl  Cholera. 

158.  California   Olive  Oil;   its  Manufacture. 

159.  Contribution  to  the  Study  of  Fermentation. 

160.  The  Hop  Aphis. 

1(51.  Tuberculosis  in  Fowls.      (Reprint.) 

162.  Commercial  Fertilizers.      (Dec.  1,  1904.) 

1(53.  Pear  Scab. 

164.  Poultry  Feeding  and  Proprietary  Foods.      (Reprint.) 

1(55.  Asparagus  and  Asparagus  Rust  in  California. 

106.  Spraying  for  Scale   Insects. 

1(57.  Manufacture  of  Dry   Wines  in  Hot  Countries. 

108.  Observations  on  Some  Vine  Diseases  in  Sonoma  County. 

1(59.  Tolerance  of  the  Sugar  Beet  for  Alkali. 

170.  Studies  in  Grasshopper  Control. 

171.  Commercial  Fertilizers.      (June  30,  1905.) 

172.  Further  Experience  in  Asparagus  Rust  Control. 

174.  A  New  Wine-Cooling  Machine. 

175.  Tomato  Diseases  in  California. 

170.  Sugar  Beets  in  the  San  Joaquin  Valley. 

177.  A  New  Method  of  Making  Dry  Red  Wine. 

178.  Mosquito  Control. 


STATION  PUBLICATIONS. 


219 


No.  179.  Commercial  Fertilizers.      (June,  1906.) 

ISO.  Resistant  Vineyards. 

181.  The  Selection  of  Seed-Wheat. 

182.  Analysis  of  Paris  Green  and  Lead  Arsenate.     Proposed  Insecticide  Law. 

183.  The  California  Tussock-moth. 

184.  Report  of  the  Plant  Pathologist  to  July  1,  1906. 

185.  Report  of  Progress  in  Cereal  Investigations. 

186.  The  Oidium  of  the  Vine. 

187.  Commercial    Fertilizers.      (January,   1907.) 

188.  Lining  of  Ditches  and  Reservoirs  to  Prevent  Seepage  Losses 

189.  Commercial  Fertilizers.     (June,  1907.) 

190.  The  Brown   Rot  of  the  Lemon. 

191.  California  Peach  Blight. 

392.  Insects  Injurious  to  the  Vine  in  California. 

193.  The  Best   Wine  Grapes  for  California ;   Pruning  Young  Vines ;   Pruning 

the  Sultanina. 

194.  Commercial  Fertilizers   (Dec.  1907). 

195.  The  Imported  Grape  Root- Worm. 

196.  Eucalyptus  in  California. 

197.  Grape  Culture  in  California;  Improved  Methods  of  Wine  Making;  Yeasts 

from  California  Grapes. 


CIRCULARS. 

No.     1.  Texas  Fever.  No.  26. 

2.  Blackleg. 

3.  Hog  Cholera.  27. 

4.  Anthrax. 

5.  Contagious  Abortion  in  Cows. 

7.     Remedies  for  Insects.  28. 

9.     Asparagus  Rust. 

10.  Reading     Course     in     Economic 

Entomology.      (Revision.)  29. 

11.  Fumigation  Practice. 

12.  Silk  Culture. 

13.  The  Culture  of  the  Sugar  Beet 

15.  Recent  Problems  in  Agriculture. 

What   a   University   Farm   is  30. 

for.  31. 

16.  Notes  on  Seed-Wheat. 

17.  Why     Agriculture     Should     be 

Taught  in  the  Public  Schools.  32. 

38.     Caterpillars  on  Oaks.  33. 
19.     Disinfection  of  Stables. 

21.  The    Advancement    of    Agricul-  34. 

tural  Education. 

22.  Defecation   of   Must   for   White 

Wine.  35. 

23.  Pure  Yeast  in  Wineries. 

24.  Olive  Pickling. 

25.  Suggestions     Regarding     Exam-  36. 

ination  of  Lands. 


Selection  and  Preparation  of 
Vine  Cuttings. 

Marly  Subsoils  and  the  Chlo- 
rosis or  Yellowing  of  Citrus 
Trees. 

A  Preliminary  Progress  Report 
of  Cereal  Investigations, 
1905-07. 

Preliminary  Announcement  Con- 
cerning Instruction  in  Prac- 
tical Agriculture  upon  the 
University  Farm,  Davisville, 
California. 

White  Fly  in  California. 

The  Agricultural  College  and  Its 
Relationship  to  the  Scheme  of 
National  Education. 

White  Fly   Eradication. 

Packing  Primes  in  Cans.  Cane 
Sugar  vs.  Beet  Sugar. 

California  State  Farmers'  In- 
stitute at  the  University 
Fa  rm. 

Southern  California  Patholog- 
ical Laboratory  and  Citrus 
Experiment  Station. 

Analyses  of  Fertilizers  for  Con- 
sumers. 


Copie*  may  be  had  on  application  to  DIBECTOB  or  EXPKBIMENT  STATION,  Berkeley,  Cal. 


BULLETIN  210.    IMPERIAL  VALLEY  SETTLERS'  CROP  MANUAL.  193 

has  been  experienced  in  drying  them.  In  other  seasons  it  has  been 
so  dry  that  some  varieties,  such  as  the  White  Adriatic,  have  been 
reported  as  drying  on  the  trees  before  fully  mature. 

There  are  no  known  serious  pests  of  the  fig  in  Imperial  Valley. 
The  large  green  beetle,  known  as  the  "Fig  E  ter"  (Allorhina  muta- 
bilis}  which  is  so  destructive  in  the  Salt  River  Valley  of  Arizona,  has 
not  yet  gained  a  foothold. 

FLAX. 

Flax  has  only  been  grown  in  a  small  experimental  way  and  very 
little  is  known  as  to  its  possibilities.  Being  a  crop  which  is  better 
suited  to  the  north  it  is  quite  sensitive  to  the  summer  heat  and  should 
be  planted  in  October  and  harvested  for  seed  or  fibre  in  the  spring. 

GOOSEBEEKY. 

It  is  very  doubtful  if  gooseberries  can  be  grown  in  the  Imperial 
Valley  with  profit,  as  they  are  not  at  all  suited  to  the  climatic  con- 
ditions. 

GRAINS. 

Barley  is  the  principal  grain  crop  of  the  valley.  It  is  better 
adapted  to  a  warm  climate  than  any  of  the  other  grains,  although 
the  hot  weather  rather  than  the  cold  is  the  limiting  factor  in  its 
growth.  The  yield  varies  from  8  to  25  sacks  per  acre,  averaging  from 
12  to  15  sacks  per  acre.  It  is  grown  for  grain,  for  winter  pasture, 
and  for  hay,  the  usual  practice  being  to  pasture  the  field  in  the  late 
fall  and  winter  (not  later  than  February)  and  to  then  let  it  go  to 
grain  or  hay.  In  this  way  it  forms  a  valuable  green  feed  when  alfalfa 
is  practically  dormant.  It  is  often  planted  in  the  alfalfa  in  the  fall 
to  furnish  a  supplementary  winter  feed.  A  good  discing  before  plant- 
ing the  barley  will  insure  a  good  stand  and  help  the  alfalfa.  It  is 
not  considered  very  profitable  when  grown  for  grain  alone,  on  a  small 
scale,  although  it  is  planted  on  most  of  the  raw  land  as  the  first  crop, 
as  it  gives  quick  returns  and  can  be  planted  before  the  land  is  per- 
fectly or  permanently  leveled.  As  the  valley  settles  iip  the  barley 
fields  will  give  way  to  more  intensively  cultivated  and  more  profitable 
crops  unless  grown  in  a  two-crop  rotation. 

Barley  will  not  sprout  during  the  very  hot  weather  in  summer, 
when  the  temperature  remains  above  110  degrees  F.  during  the  day, 
even  when  the  proper  moisture  conditions  are  supplied.  The  seed  is 
sown  any  time  after  the  middle  of  September  to  the  middle  of  Febru- 
ary. If  winter  pasture  TS  desired  the  seed  is  usually  planted  about 
the  first  of  October.  When  grain  alone  is  wanted  the  barley  is  usually 


194  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

sown  in  the  latter  part  of  December  or  the  first  part  of  January.  The 
grain  ripens  in  May.  Broadcasting  the  seed,  followed  by  harrowing, 
is  the  common  method  of  planting.  From  20  to  40  pounds  of  seed  is 
used  per  acre  when  sown  in  the  early  fall  and  from  40  to  75  pounds 
when  sown  in  the  spring  or  winter,  since  the  spring  sown  grain  does 
not  tiller  or  stool  as  does  that  sown  in  the  fall.  The  usual  practice  is 
to  allow  the  land  to  reseed  itself  or  volunteer  after  the  first  year,  as  the 
scattering  caused  by  allowing  the  ripened  grain  to  stand  for  a  long 
time  in  the  severe  spring  winds  before  harvesting  leaves  plenty  of  seed 
on  the  ground  to  come  up  after  the  fall  irrigation. 

The  land  is  sometimes  irrigated  before  planting  but  usually  the 
seed  is  put  in  dry  soil  and  then  irrigated.  The  amount  of  water  needed 
to  mature  the  crop  varies  with  the  different  soils.  Usually  five  irriga- 
tions are  sufficient  if  given  at  the  proper  time. 

Oats  have  been  tried  but  have  never  proved  to  be  a  great  success, 
mainly  because  they  are  more  adapted  to  a  colder  and  more  moist 
climate.  The  Texas  Red  variety  yields  fairly  well  but  does  not  seem 
to  be  as  profitable  as  barley. 

Wheat  of  several  varieties  has  been  grown  in  the  valley  and  has 
given  good  results  in  most  cases.  Wheat  is  not  so  well  adapted  to 
this  locality  as  barley,  as  shown  by  the  fact  that  it  has  been  almost 
entirely  supplanted  by  barley  during  the  past  nine  years.  The  rust 
which  attacked  the  wheat  in  1905  was  no  more  serious  than  in  other 
parts  of  the  State  that  same  year,  consequently  the  statement  that 
wheat  is  more  susceptible  to  rust  in  Imperial  Valley  than  in  other 
localities  is  not  true.  The  general  cultural  treatment  for  wheat  is 
the  same  as  that  for  barley. 

GRAPE    GROWING   IN   THE    IMPERIAL   VALLEY.7 

From  the  beginning  of  the  settlement  of  the  Imperial  Valley,  about 
ten  years  ago,  the  growing  of  grapes  has  received  a  great  deal  of 
attention.  There  are  at  present  about  two  hundred  growers  of  grapes, 
possessing  vineyards  of  various  sizes,  from  one  hundred  vines  up  to 
one  hundred  acres  or  more,  scattered  over  the  Valley  from  Brawley 
to  Calexico.  These  vines  are  all  of  vinifera  varieties,  only  an  occa- 
sional vine  of  a  labrusca  or  other  East  American  variety  being  found. 
The  total  area  in  vines  is  probably  about  500  to  600  acres,  although 
the  County  Recorder  places  the  number  of  vines  in  the  county  in 
1909  at  only  159,565. 

The  rapidity  of  growth  and  vigor  of  the  vines  is  remarkable  and 

7  By  Frederic  T.  Bioletti,  Viticulturist,  California  Experiment  Station. 


BULLETIN  210.    IMPERIAL  VALLEY  SETTLERS'  CROP  MANUAL.  195 

their  fruitfulness  and  earliness  of  bearing  scarcely  less  so.  The  fruit 
ripens  from  two  to  six  weeks  earlier  than  in  any  other  part  of  Cali- 
fornia except  in  the  Coachella  Valley,  which  is  part  of  the  same 
climatological  area. 


Fig.  26. — Three-year-old  Sultanina  vine  on  Reid  ranch. 

With  these  favorable  conditions  there  seems  to  be  every  reason  to 
anticipate  that  the  growing  of  grapes  will  be  a  very  profitable  industry 
in  the  valley.  On  this  point,  however,  there  is  a  great  diversity  of 
opinion  among  the  growers.  While  some  growers  seem  to  have  done 
very  well,  others  have  failed  to  make  a  profit  out  of  their  crops.  One 
of  the  reasons  given  for  failure  to  realize  a  profit  is  the  high  cost  of 
transportation  and  labor.  But  the  price  of  such  grapes  as  are  accepted 


196  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

by  the  packers  is  also  high,  being  $50  to  $60  per  ton  at  the  packing 
house  in  1910.  Another  reason  given  is  that  the  grapes  grown  in 
the  Imperial  Valley  have  poor  shipping  and  keeping  qualities  and  that 
only  a  small  proportion  get  to  the  market  in  good  condition.  As  a 
matter  of  fact,  some  of  the  grapes  grown  in  the  valley  have  excep- 
tionally good  keeping  and  shipping  qualities.  The  true  main  reason 
for  the  failure  to  make  grape  growing  pay  seems  to  lie  in  the  failure 
to  adopt  suitable  methods  of  growing  and  treating  the  vines  and 
grapes.  The  climatic  and  soil  conditions  are  peculiar  and  different 
from  those  of  any  other  grape  growing  section  of  California,  and 
special  methods  are  necessary  to  insure  profitable  returns.  The  full 
profit  of  the  industry  will  be  realized  only  when  the  methods  best 
adapted  to  the  conditions  are  generally  known  and  followed.  What 
these  best  methods  are,  study,  time  and  experience  alone  can  determine. 

Every  phase  of  the  subject,  from  the  preparation  of  the  ground  for 
planting  to  the  delivery  of  the  grapes  to  the  consumer,  requires  in- 
vestigation. Already,  indeed,  a  considerable  amount  of  experimenta- 
tion, intentional  and  otherwise,  has  been  carried  out.  Grape  growers 
from  widely  differing  viticultural  sections  have  been  planting  and 
cultivating  vines  in  the  valley  for  several  years,  all  modifying  their 
practice  more  or  less  in  accordance  with  the  customs  of  their  old 
homes.  A  large  number  of  vinifera  varieties  have  been  introduced 
and  tested.  On  many  points,  therefore,  there  is  experimental  data  on 
which  to  make  comparisons  and  form  conclusions. 

At  present,  the  grapes  are  grown  exclusively  for  early  shipment  as 
table  grapes  or  for  local  consumption.  The  principal  shipping  season 
extends  from  about  the  middle  of  June  to  the  end  of  July,  varying 
somewhat  in  different  years.  The  great  bulk  of  the  grapes  consists  of 
Sultanina  (Thompson's  Seedless),  Malaga,  and  Muscat  of  Alexandria, 
ripening  in  the  order  named.  The  shipments  of  Malaga  far  exceed 
those  of  all  other  varieties  combined.  The  season  could  undoubtedly 
be  lengthened  by  the  use  of  varieties  ripening  before  the  Sultanina 
and  of  very  late  varieties.  The  latter  would  come  in  competition  with 
varieties  from  other  sections,  but  being  very  distinct  in  character  they 
would  undoubtedly  find  a  market. 

Preparation  of  the  Soil. — It  is  very  important  that  the  vines  should 
have  strong  root  systems  penetrating  deeply  into  the  soil. 

In  many,  probably  in  most,  of  the  vineyards  of  the  valley  the  vines 
have  shallow  spreading  roots  confined  to  the  top  foot  of  soil.  In 
several  cases  examined,  no  roots  as  large  as  a  pencil  were  found  below 
ten  inches  from  the  surface.  Such  vines  may  grow  vigorously  and 


BULLETIN  210.    IMPERIAL  VALLEY  SETTLERS'  CROP  MANUAL. 


197 


even  bear  heavy  crops  so  long  as  the  layer  of  soil  in  which  the  roots 
lie  is  kept  moist.  This  requires  numerous  irrigations  throughout  the 
growing  season.  The  omission  of  one  irrigation  may  seriously  damage 
or  kill  vines  in  this  state  of  unstable  equilibrium.  Even  when  the 
irrigations  are  not  neglected  the  conditions  are  not  favorable  for  the 
best  results.  Where  the  roots  are  confined  to  the  upper  twelve  inches 


Fig.  27. — Vine  with  shallow  horizontal  root  system,  very  objectionable. 

of  soil  they  are  subject  to  constant  changes  in  moisture  and  tempera- 
ture. This  condition  is  unfavorable  to  the  proper  development  and 
nourishment  of  the  fruit  and  does  not  tend  towards  the  production  of 
grapes  of  the  highest  eating  or  shipping  qualities. 

With  a  deep  root  system  penetrating  six,  eight,  or  more  feet  in 
depth,  the  growth  of  the  vine  is  more  regular,  the  grapes  ripen  more 
regularly,  are  firmer  and  of  better  flavor.  Moreover,  fewer  irrigations 
are  needed  and  the  omission  of  one  will  not  have  such  serious  con- 
sequences.. 

The  position  of  the  main  roots  of  the  vine  is  fixed  by  the  growth 
of  the  first  year.  Where  this  growth  will  be  is  determined  by  the  soil 
conditions  and  not  by  the  length  or  position  of  the  cutting.  The  roots 


198  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

will  grow  where  they  find  the  most  favorable  temperature  and  mois- 
ture. If  the  soil  at  two  feet  is  dry  the  roots  will  not  grow  there, 
however  long  the  cutting  may  have  been.  If  the  soil  at  six  feet  has 
the  proper  degree  of  moisture  the  roots  will  go  to  that  depth,  however 
short  the  cuttings.  Before  planting  the  vineyard,  therefore,  the  soil 
must  be  thoroughly  soaked  down  to  five  or  six  feet  at  least. 

Owing  to  the  filling  up  of  the  soil  pores  with  the  silt  carried  by  the 
irrigating  water,  this  deep  wetting  cannot  be  accomplished  on  hard 
soils  by  ordinary  furrow  irrigation  or  a  single  flooding  in  the  usual 
manner.  Some  more  efficient  method  of  wetting  such  soils  must  be 
found  if  the  vines  are  to  be  placed  on  a  stable  basis. 

Probably  the  growing  of  alfalfa  on  the  land  for  two  or  three  years 
before  planting  would  be  the  best  means.  The  repeated  heavy  flood- 
ings  would  finally  moisten  the  soil  down  to  the  required  depth  and  the 
alfalfa  would  improve  the  humus  and  nitrogen  contents  of  the  soil. 
Another  method  adopted  with  success  by  some  growers  is  to  check 
up  the  land  with  levees  high  enough  to  allow  of  flooding  each  check 
to  a  depth  of  one  or  two  feet.  "When  the  water  of  this  first  flooding 
has  disappeared  by  soaking  in  and  evaporation  the  check  is  flooded 
again.  Two  or  three  floodings  of  this  kind  will,  in  most  cases,  wet 
the  soil  down  sufficiently  deep.  Another  method  suggested  is  a  pro- 
longed slow  irrigation  with  very  small  furrows.  This,  however,  is 
laborious  and  less  certain  to  moisten  all  the  soil  equally. 

Choice  of  Cuttings  and  Roots. — If  the  soil  is  properly  prepared  by 
soaking  and  deep  plowing,  cuttings  should  succeed  almost  as  well  as 
roots. 

The  cuttings  should  be  chosen,  made  and  handled  properly.8  With 
care  in  planting  and  cultivation,  ninety  per  cent,  or  more  of  them 
should  make  a  good  growth.  Those  which  miss  should  be  carefully 
replaced  the  following  year  with  rooted  vines. 

The  length  of  the  cutting  is  not  of  great  importance  providing  it 
is  long  enough  not  to  run  any  risk  of  becoming  dry  before  it  roots. 
From  fourteen  to  sixteen  inches  is  a  convenient  length.  Longer  cut- 
tings simply  increase  the  cost  of  planting  without  any  corresponding 
benefit. 

The  soil,  after  irrigating,  should  be  plowed,  harrowed,  and  gotten 
into  perfect  condition  before  planting.  The  cuttings,  after  soaking 
in  water  for  one  to  three  days,  should  be  planted  with  care  to  avoid 
drying.  The  soil  should  be  packed  tightly  around  the  cutting  from 


8  See  Circular  26,  "The  Selection  and  Preparation  of  Vine  Cuttings,"  Agri- 
cultural Experiment  Station.  Berkeley,  California. 


BULLETIN  210.    IMPERIAL  VALLEY  SETTLERS'  CROP  MANUAL. 


199 


the  bottom  nearly  to  the  top  and  only  one  bud  left  above  the  surface. 

If  the  soil  is  sufficiently  moist  when  the  cuttings  are  planted,  no 

irrigation  will  be  necesary  for  several  weeks.    Repeated  cultivation  to 

keep  the  surface  loose  and  so  preserve  the  moisture  already  in  the  soil 


Fig.  28. — A  vine  pruned  too  low,  grapes  massed  together  and  lying  on  the 

ground. 


is  better  than  any  irrigation  at  this  time.  By  keeping  the  top  four 
to  six  inches  of  soil  loose  and  dry  the  moisture  below  that  depth  is 
prevented  from  escaping  and  the  roots  are  encouraged  to  take  a  down- 
ward direction.  If,  however,  the  soil  has  become  a  little  too  dry  on 
top  before  planting,  a  small  stream  of  water  should  be  run  down  each 


200  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

row,  giving  the  soil  around  each  cutting  a  good  soaking.  Care  should 
be  taken  to  avoid  flooding  the  whole  vineyard,  as  this  will  tend  to 
form  a  crust  and  make  it  difficult  to  preserve  the  moisture-holding  soil 
mulch. 

During  the  summer,  the  young  vines  should  be  kept  growing  by 
cultivation  and,  when  necessary,  irrigation.  Frequent  shallow  irriga- 
tion should  be  avoided.  Some  means  of  getting  the  water  down  below 
the  top  eight  or  ten  inches  should  be  found.  Shallow  irrigation  the 
first  year  produces  shalloiv  rooted  vines  and  shallow  rooted  vines  in 
the  hot  dry  climate  of  Imperial  have  a  precarious  existence. 

Form  of  the  Vine. — Just  as  the  general  character  of  the  root  system 
is  determined  by  the  growth  of  the  first  year,  so  the  form  of  the  mature 
vine  is  determined  by  the  growth  and  training  of  the  first  one,  two, 
or  three  years.  In  fact,  in  Imperial  County  the  growth  is  often  so 
large  the  first  year  that  the  treatment  the  vine  receives  during  this 
year  determines  whether  we  have  a  vine  which  can  be  handled  with 
economy  and  profit  or  one  which  costs  far  more  than  it  ought  to 
prune  and  cultivate,  and  which  produces  only  second  rate  grapes  of 
poor  shipping  qualities.  A  considerable  amount  of  extra  care  and 
expense  the  first  two  years  will  undoubtedly  be  more  than  justified 
and  returned  by  saving  of  expense  and  increased  returns  from  the 
bearing  vineyard. 

A  poorly  shaped  vine,  lying  on  the  ground,  with  crossing  and  inter- 
locking arms  is  difficult,  in  fact  impossible,  to  prune  and  cultivate 
properly.  The  grapes  on  such  a  vine  lie  on  the  gromnd,  become  soiled, 
moldy  and  ripen  unequally.  When  they  are  gathered,  the  best  bunches 
cannot  be  taken  from  the  vines  without  breaking  and  bruising  a  large 
proportion  of  the  berries.  The  result  is  that  only  about  fifty  per  cent, 
of  the  grapes  will  be  accepted  by  the  packers,  and  this  fifty  per  cent, 
is  often  handled  at  a  loss  owing  to  poor  keeping  qualities. 

What  the  best  form  for  the  vine  is,  under  the  conditions  of  Imperial 
County,  it  is  impossible  to  say  with  our  present  experience.  But 
there  is  room  for  much  improvement  in  the  present  practice  of  a 
majority  of  the  vineyards  and  there  are  certain  characteristics  that 
may  be  accepted  as  necessary  for  a  good  vine. 

In  the  first  place  the  vine  should  have  a  clear,  straight  trunk 
without  arms,  spurs  or  branches,  at  least  fifteen  inches  high.  At  the 
top  of  this  trunk  the  arms  bearing  the  fruiting  wood  should  be  so 
arranged  that  the  bunches  of  grapes  hang  free  from  each  other  and 
from  growing  shoots.  As  much  as  possible  each  bunch  should  be 


BULLETIN  210.    IMPERIAL  VALLEY  SETTLERS'  CROP  MANUAL.  201 

exposed  equally  to  light  and  air  and  should  be  so  placed  that  it  is  pos- 
sible to  gather  it  by  the  stem  without  breaking  or  even  touching  a 
berry. 


Fig.  29. — Mature  vine  of  proper  shape. 


This  may  seem  an  impracticable  refinement.  It  should  be  remem- 
bered, however,  that  bunches  of  perfect  grapes  of  good  shipping 
qualities  can  be  sold  for  $50  per  ton,  while  poor  grapes  are  worth 
only  about  $5  for  hog  feed.  The  gross  returns,  therefore,  from  five 
acres  of  good  shipping  grapes  are  equal  to  those  of  fifty  acres  of  poor 
grapes  and  the  net  profits  may  be  ten  times  as  great.  Many  growers 
could  undoubtedly  very  much  increase  their  profits  by  concentrating 
their  labor  and  expense  on  half  the  area  they  now7  cultivate. 


202 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 


For  most  of  the  varieties  now 
grown  in  Imperial  County  the  open 
vase  form  of  vine  is  an  excellent 
one.  In  this  form,  six  to  eight  arms, 
arranged  symmetrically  around  the 
head  or  top  of  the  15  to  18  inch 
trunk,  spread  out  in  all  directions, 
rising  at  an  angle  of  about  45°  to 
30°  from  the  vertical.  This  form 
makes  it  possible  to  cultivate  close 
up  to  the  vine  without  injuring  it 
and  arranges  the  bearing  wood  in 
such  a  way  that  the  bunches  are 
well  spaced  without  interference 
and  easy  to  get  at. 

This  or  any  other  suitable  form 
cannot  be  attained  without  the  use 
of  stakes.  Where  the  vines  make 
a  large  growth  the  first  year,  the 
stakes  should  be  placed  when  the 
vines  are  planted.  The  way  of 
handling  the  young  vines  to  get 
them  into  the  desired  shape  is  de- 
scribed in  Bulletin  193,  pp.  146  to 
155.9 

Irrigation. — Among  the  most  difficult  problems  are  those  connected 
with  the  proper  irrigation  of  the  vineyards. 

The  desirability  of  deep  and  not  too  frequent  irrigation  of  young 
vines  has  already  been  pointed  out.  It  is  equally  necessary  for  bear- 
ing vines.  Some  growers  of  small  vineyards  keep  their  vines  irrigated 
almost  constantly.  Other  vineyards  are  left  five  months  without 
irrigation.  The  proper  number  will  depend  in  any  particular  case 
principally  on  the  position  of  the  roots.  With  deep  rooted  vines  three 
or  four  thorough  irrigations  during  the  year  seem  to  be  all  that  are 
necessary,  providing  the  cultivation  is  well  done. 

The  best  time  for  these  irrigations  is  perhaps  not  yet  determined. 
In  this  respect  two  important  points  should  be  kept  in  mind. 

First :  Any  rapid  and  considerable  addition  to  the  moisture  of  the 
soil  during  the  last  stages  of  ripening  injures  the  shipping  qualities 
of  the  grapes.  The  grapes  become  watery,  surcharged  with  sap  and 


Fig.  30. — Young  vine  staked  and 
properly  started. 


»  Bulletin  193,  Agricultural  Experiment  Station,  Berkeley.  California. 


BULLETIN  210.    IMPERIAL  VALLEY  SETTLERS'  CROP  MANUAL.  203 

are  easily  broken  or  detached  from  the  pedicle  by  a  touch.  The  last 
irrigation  before  gathering  the  crop,  therefore,  should  not  be  later 
than  the  commencement  of  ripening.  If  the  irrigation  and  cultiva- 
tion has  been  properly  done  up  to  that  point  the  soil  should  contain 
enough  moisture  to  bring  the  grapes  to  the  shipping  point  of  ripeness. 

Second:  A  vine,  for  the  best  results,  should  have  a  dormant  or 
resting  period.  In  the  tropics,  where  the  atmosphere  is  constantly 
warm  and  the  soil  constantly  moist,  the  vine  becomes  an  evergreen. 
The  grapes  produced  under  these  conditions  are  of  poor  quality, 
deficient  in  sugar  and  flavoring.  The  growth  of  the  vine  is  not 
checked  completely  by  cold  until  the  mean  daily  temperature  falls 
below  48°  F.  The  mean  daily  temperature  for  December,  the  coldest 
month  at  El  Centre  in  1909,  was  50.25°  F.  If  this  alone  controlled 
the  dormancy  the  vine  should  remain  evergreen.  There  are,  however, 
one  or  two  days  each  year,  usually  in  December  or  January,  when  the 
temperature  drops  to  the  freezing  points  or  a  few  degrees  below.  This 
is  sufficient  to  make  the  vine  lose  its  leaves  and  remain  dormant  for  a 
short  time  before  the  new  buds  swell. 

For  the  best  results  the  vine  seems  to  need  about  three  months  rest. 
In  order  to  insure  this,  the  vine  should  commence  its  dormant  season 
before  the  December  or  January  frost.  This  can  be  controlled  by 
suitable  management  of  the  irrigation. 

When  the  moisture  content  of  the  soil  falls  below  a  certain  per- 
centage the  rine  ceases  to  grow.  When  the  soil  becomes  still  dryer 
the  leaves  turn  yellow  and  fall  and  the  vine  becomes  dormant.  The 
irrigation  should  be  so  applied,  therefore,  that  the  vines  are  caused 
to  become  dormant  by  drying  of  the  soil,  sometime  in  November.  The 
drying  of  the  soil  should  not  be  too  early  or  too  intense  or  the  vines 
may  be  injured. 

After  the  grapes  are  gathered  a  very  important  part  of  the  work 
of  the  leaves  still  remains  to  be  accomplished.  This  work  is  the 
ripening  of  the  young  canes  and  the  laying  up  of  stores  of  starch  in 
the  buds  and  other  organs  of  the  vine.  It  is  on  the  abundance  of  these 
stores  that  the  growth  and  crop  of  the  following  year  depend. 

This  laying  up  of  winter  stores  by  the  action  of  the  leaves  requires 
a  month  or  six  weeks  and  takes  place  most  abundantly  when  the  vine 
is  provided  with  a  large  number  of  mature  green  leaves  but  is  making 
little  or  no  new  growth.  In  some  cases  an  irrigation  immediately 
after  the  gathering  of  the  grapes  would  be  necessary  or  advisable  to 
prevent  the  premature  dropping  of  the  leaves. 


204  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

Intercalary  Crops. — Many  growers  have  been  raising  melons  and 
other  annual  crops  between  the  vines,  especially  during  the  first  year 
or  two.  It  is  doubtful  whether  this  is  good  practice  so  far  as  the 
success  of  the  vines  is  concerned.  Any  crop  which  requires  frequent 
irrigations  leads  to  the  keeping  of  the  top  layer  of  soil  unduly  wet 
and  promotes  the  shallow  rooting  of  the  vines.  It  is  possible  that  by 
growing  the  intercalary  crop  in  the  middle  of  the  row  and  irrigating 


Fig.  31. — Cantaloupes,  apricots,  and  grapes  growing  together. 

in  such  a  way  that  the  top  soil  near  the  vines  is  not  moistened  by  each 
application  of  water  that  no  harm  would  be  done  to  the  vines  when 
young.  Any  crop  which  requires  constant  or  frequent  irrigation 
should  not  be  grown  among  bearing  vines  or  the  quality  of  the  fruit 
will  suffer. 

Other  growers  make  mixed  plantings  of  fruit  trees,  peaches, 
apricots,  etc.,  with  vines.  There  are  indications  that  this  may  be  a 
good  practice.  The  trees  break  the  force  of  the  wind  and  make  it 
easier  to  raise  the  vines  and  give  them  a  suitable  shape. 

Diseases  of  the  Vine. — So  far  no  fungous  disease  of  the  vine  of 
any  importance  has  been  noted  in  Imperial  County.  The  dryness  of 
the  air  during  the  growing  and  ripening  season  of  the  early  grapes 
makes  it  unlikely  that  there  should  ever  be  much  trouble  from  this 
source.  The  moister  weather  which  occasionally  occurs  after  mid- 
summer might  involve  danger  in  this  respect,  but  no  fungous  disease 
has  yet  been  called  to  the  attention  of  the  Experiment  Station. 


BULLETIN  210.    IMPERIAL  VALLEY  SETTLERS'  CROP  MANUAL. 


205 


206  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

The  only  serious  insect  pests  that  have  been  noted  are  the  vine 
hopper  and  a  species  of  thrips. 

The  vine  hopper  seems  at  present  confined  almost  entirely  to  one 
locality,  but  it  is  possible  that  it  may  become  as  serious  a  pest  as  it 
is  in  many  other  parts  of  California.  The  only  method  of  control 
which  so  far  offers  much  chance  of  success  can  be  applied  effectively 
only  to  vines  which  have  a  distinct  trunk  with  all  arms  well  off  the 
ground.10  This  offers  another  forcible  reason  for  adopting  the  mode  of 
training  recommended. 

The  thrips  have  been  found  in  large  numbers  on  the  vine  blossoms. 
So  far  as  noted,  no  particular  damage  seems  to  have  been  done,  as 
their  attacks  were  confined  to  the  second  crop. 

Several  cases  of  dying  vines  were  investigated.  In  some  cases  the 
numbers  of  dying  and  dead  vines  was  large.  In  all  cases  the  trouble 
seems  to  be  due  to  mistakes  in  irrigation  or  cultivation.  In  the  worst 
cases  the  trouble  seemed  to  be  due  to  the  shallow  rooting  of  the  vines 
and  their  consequent  sensitiveness  to  heat  and  drouth. 

This  valley,  like  all  of  southern  California,  seems  to  be  so  far  free 
from  phylloxera.  It  is  advisable,  therefore,  that  the  present  strict 
quarantine  should  be  maintained  against  all  rooted  vines  from  outside 
the  county  and  especially  from  eastern  states  and  Europe.  The  exclu- 
sion of  unrooted  cuttings,  however,  works  an  unnecessary  hardship  on 
those  growers  who  wish  to  plant  or  experiment  with  varieties  which 
cannot  be  obtained  in  the  county.  There  is  very  little  danger  from 
cuttings  grown  in  California  and  this  danger  can  be  eliminated  by 
disinfection  under  the  direction  of  the  horticultural  quarantine  officer. 

Handling  the  Grapes. — The  profitable  production  of  grapes  in 
Imperial  County  at  present  and  probably  in  the  future  can  be  carried 
on  only  by  the  methods  of  intensive  culture.  Wholesale,  careless 
methods  may  in  some  regions  yield  a  profit  in  growing  wine  grapes 
or  raisin  grapes,  but  the  conditions  for  these  industries  are  not  at 
present  favorable  in  this  region.  Fine  early  table  grapes  that  can  be 
placed  on  the  eastern  market  in  prime  condition  will  command  high 
prices.  Inferior  grapes  or  grapes  which  spoil  before  they  reach  the 
consumer  are  hard  to  give  away  and  can  never  yield  a  permanent 
profit. 

Every  reasonable  effort,  therefore,  should  be  made  to  produce  only 
the  choicest  fruit.  An  extra  expenditure  of  $25  to  $50  per  acre  is 
justified  if  the  salable  value  of  the  crop  is  increased  $100  or  $150  per 
acre. 


10  See  Bulletin  198  and  Bulletin  193,  pp.   111-116,  Agricultural  Experiment 
Station,  Berkeley,  California. 


BULLETIN  210.    IMPERIAL  VALLEY  SETTLERS'  CROP  MANUAL.  207 

The  preceding  suggestions  regarding  improvements  in  planting, 
pruning,  training  and  irrigation  have  this  in  vew.  The  proper  handing 
of  the  grapes  is  no  less  important.  A  bunch  of  grapes  which  is  perfect 
in  the  vineyard  may  be  easily  ruined  by  careless  gathering  or  hauling 
before  it  reaches  the  packing  shed. 

The  grapes,  in  gathering,  should  be  touched  as  little  as  possible 
and  handled  only  by  the  peduncle  or  main  stem.  They  should  be 
placed  carefully  in  wide  shallow  boxes  in  a  single  layer.  In  these 
boxes  they  should  remain  for  twelve  to  twenty-four  hours  to  wilt 
slightly  and  lose  their  rigidity  before  packing  and,  if  possible,  before 
hauling.  If  they  are  warm  when  picked  they  will  wilt  more  rapidly 
and  proper  packing  without  injury  to  the  berries  will  be  facilitated. 
Hauling  to  the  packing  house  should  be  done  very  carefully,  prefer- 
ably in  wagons  provided  with  springs.  The  grapes  should  be  pro- 
tected from  the  dust  and  the  direct  rays  of  the  sun,  and  the  boxes 
should  be  so  stacked  that  there  is  no  danger  of  crushing  the  grapes. 

Removal  of  Suckers. — Many  bunches  are  injured  in  gathering, 
owing  to  the  necessity  of  freeing  them  from  suckers  and  water-sprouts 
which  have  grown  through  the  middle  of  the  bunch.  Some  of  the 
grapes  are  pulled  off,  some  broken  and,  worst  of  all,  some  of  them  are 
slightly  loosened  around  the  pedicel  or  stalklet.  Most  of  the  broken 
berries  can  be  removed  by  the  trimmers  in  the  packing  house,  but 
many  of  those  simply  loosened  will  escape  their  scrutiny  and  are  a 
fruitful  cause  of  decay. 

By  going  over  the  vineyard  soon  after  the  grapes  have  set,  inter- 
fering shoots  can  be  removed  or  freed  from  the  bunches.  The  cost 
of  this  should  be  abundantly  returned  by  saving  in  labor  of  gather- 
ing and  trimming  and  especially  in  improvement  in  the  shipping 
qualities  of  the  whole  crop.  In  long  shipments  one  spoiled  bunch  may 
infect  a  whole  crate. 

Thinning.— htemy  otherwise  suitable  grapes  do  not  ship  well  on 
account  of  the  excessive  compactness  of  the  bunch.  A  compact  bunch 
is  difficult  to  pack  without  injury  and  cannot  be  freed  from  imperfect 
berries  without  spoiling  good  berries. 

This  excessive  compactness  can  be  prevented  by  thinning  before 
the  berries  are  one-third  grown.  Thinning,  moreover,  increases  the 
size  of  the  berries,  hastens  ripening,  promotes  coloring,  and  lessens 
some  forms  of  sunburn.  The  practice  is  regularly  followed  with 
success  by  many  growers  of  Tokay,  Black  Morocco,  and  other  grapes 
in  northern  California.  While  apparently  costly,  the  expense  is  often 
more  than  counterbalanced  by  the  saving  in  trimming  of  the  ripe 
grapes.  The  increase  of  quality  thus  becomes  a  net  gain. 


208 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 


The  bunches  are  thinned  at  any  time  after  the  berries  have  set  and 
before  they  have  reached  one-third  their  mature  size. 

No  bunches  are  removed,  but  only  a  certain  proportion  of  the 
berries  of  each  bunch.  The  number  of  berries  to  be  removed  will 
depend  upon  how  compact  the  unthinned  bunches  usually  become. 


Fig.  33. — Bunch  of  green  grapes  before  thinning. 

In  general,  it  will  vary  from  one  third  to  one  half  of  the  total  number. 
The  thinning  is  effected  by  cutting  out  several  of  the  side  branchlets 
of  the  bunch.  The  branchlets  should  be  removed  principally  from 
the  part  of  the  bunch  which  has  most  tendency  to  compactness,  usually 
the  upper  part.  The  work  can  be  done  very  rapidly  as  no  great  care 
is  necessary  in  preserving  the  shape  of  the  bunch.  However  irregular 


BULLETIN  210.    IMPERIAL  VALLEY  SETTLERS'  CROP  MANUAL.  209 

or  one-sided  the  bunch  looks  immediately  after  thinning,  it  will  round 
out  and  become  regular  before  ripening. 


Fig.  34. — Bunch  of  green  grapes  after  thinning. 

A  long,  narrow  bladed  knife  or  a  pair  of  grape  trimming  scissors 
can  be  used  conveniently  for  this  work. 

Varieties. — A  very  large  number  of  varieties  have  been  planted  in 
Imperial  Valley.  On  a  recent  trip  about  sixty  varieties  were  seen  in 


210  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

bearing.  Many  of  these  were  too  young  or  too  few  for  a  judgment  to 
be  formed  as  to  their  value.  The  principal  object  of  the  growers  who 
were  testing  these  varieties  seemed  to  be  to  find  a  variety  of  good 
shipping  qualities  earlier  than  the  Malaga  and  especially  to  find  a 
suitable  black  or  red  grape.  There  seemed  to  be  a  general  impression 
that  grapes  ripening  much  after  July  first  were  poor  in  quality  and 
did  not  ship  well. 

Early  Grapes. — Several  varieties  were  seen  ripening  one  to  two 
weeks  before  the  Malaga  and  Sultanina  (Thompson's  Seedless). 

The  Luglienga  has  been  planted  by  several  growers  but  is  gener- 
ally disappointing.  It  ripens  very  early,  but  the  bunches  are  small 
and  compact  and  the  berries  juicy  and  soft.  It  is  inferior  in  these 
respects  to  the  same  variety  grown  in  the  Coachella  Valley.  It  is 
probable  that  it  could  be  much  improved  by  longer  pruning  and 
thinning  of  the  bunch. 

The  Chasselas  dore  and  Chasselas  rose  (White  and  Red  Sweet- 
water)  have  the  same  defects  as  the  Luglienga  and  seem  subject  to 
sunburn. 

The  earliest  black  grape  seen  was  the  Blue  Portuguese,  but  it  has 
little  to  recommend  it  except  earliness.  The  berries  are  small  and  too 
juicy  for  distant  shipping.  The  Bellino  is  a  black  grape  almost  as 
early  as  the  Blue  Portuguese  and  very  superior  in  appearance  and 
shipping  qualities.  This  is  the  most  promising  of  the  early  black 
grapes. 

A  few  of  the  Persian  varieties  were  found  bearing  in  several  vine- 
yards and  some  of  them  promise  to  be  superior  to  any  of  the  early 
grapes  yet  tested.  They  have  nearly  all  a  family  resemblance  in 
delicacy  of  texture  and  flavor,  combined  with  a  certain  absence  of 
juiciness  which  promises  well  for  their  shipping  qualities.  They  vary 
considerably  in  color,  shape,  and  time  of  ripening. 

The  varieties  known  as  Persians  Nos.  21,  23,  24,  and  26,  resemble 
each  other  very  closely.  They  are  all  yellowish  white,  short,  cylin- 
drical and  very  early,  ripening  one  or  two  weeks  before  the  Sultanina 
and  at  least  as  early  as  the  Luglienga  and  Chasselas.  They  are  larger 
and  of  finer  appearance  than  these  varieties.  The  bunches  are  well 
filled  but  loose  and  easy  to  pack.  The  Dizmar  and  Khalille,  also 
Persian  varieties,  belong  to  the  same  group.  The  Chavooshee  is  a 
long  white  grape  ripening  about  the  same  time.  The  Hutab,  Alakakee, 
and  Risk  Baba  are  large,  elongated,  curved  white  grapes  ripening  a 
little  earlier  than  the  Malaga  and  are  all  very  striking  in  appearance 
and  promise  to  be  of  good  shipping  quality. 


BULLETIN  210.    IMPERIAL  VALLEY  SETTLERS'  CROP  MANUAL.       -  ^          211 

The  red  Persian  grapes,  the  Paykanee  and  the  Ashakanee,  should 
be  well  tested.  They  are  very  early,  of  excellent  quality,  and  very 
ornamental.  The  former  seems  to  be  the  best  and  is  the  only  one 
fruiting  in  the  Imperial  Valley.  It  is  of  a  bright  red  tint,  large, 
elongated  and  pointed.  While  very  soft  and  delicate  to  eat  it  is  not 
juicy,  has  large  loose  bunches  and  would  probably  ship  as  well  as  the 
Sultanina. 

The  Askaree,  the  only  black  Persian  grape  we  have,  has  not  yet 
been  tested  in  the  Imperial  Valley.  It  has  most  of  the  good  qualities 
of  the  other  Persians  but  is  a  little  more  delicate  and  might  be 
difficult  to  ship. 

The  varieties  grown  under  the  names  Persian  20,  22,  and  25  are 
small,  juicy,  and  unsuited  for  shipping. 

The  Dattier  de  Beirut  is  a  large  oval  grape,  ripening  before  the 
Malaga  and  should  be  tried. 

Of  varieties  ripening  about  the  same  time  as  the  Malaga  the  most 
promising  is  the  Olivette  de  Cadenet.  Several  vines  of  this  variety 
were  seen  in  fruit  and  in  all  cases  they  were  doing  well.  The  grapes 
resemble  very  closely  those  of  the  Malaga  but  seem  to  be  of  a  little 
better  quality  both  for  eating  and  shipping. 

The  Golden  Queen  and  the  Kurtelaska  are  also  promising  varieties. 
They  are  white,  large,  nearly  round,  firm,  and  heavy  bearers. 

The  Bermestia  violacea  is  a  large,  oval,  reddish  grape  ripening 
about  the  same  time  and  may  be  a  valuable  variety. 

The  Black  Damascus  is  the  only  black  grape  planted  -  in  large 
quantities  and  it  is  generally  successful.  It  is  a  heavy  bearer,  pro- 
ducing large  bunches  of  fine  oval  grapes  that  ship  well. 

A  Black  Muscat  and  the  Moscatello  fino  are  also  promising.  They 
bear  well,  the  grapes  are  highly  flavored  and  large,  and  they  ripen 
sufficiently  early.  They  would  probably  be  too  delicate  for  distant 
shipment. 

GEASSES. 

Australian  Rye  Grass  (Lolium  multiflorum),  being  an  annual  does 
well  during  the  winter  months,  but  dies  out  during  the  summer.  It 
is  an  excellent  grass  for  a  winter  lawn,  being  frequently  planted  in 
Bermuda  lawns  in  the  fall.  During  the  winter  it  appears  very  much 
like  common  blue  grass. 

Bermuda  grass  (Cynodon  dactylon)  is  a  pest  on  ranch  lands  in  the 
valley,  but  is  grown  for  a  lawn  on  many  of  the  town  lots.  It  makes 


212  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION. 

a  very  vigorous  growth  during  the  summer,  but  lies  dormant  during 
the  winter.  On  the  farms  the  Bermuda  grass  spreads  very  rapidly 
by  both  seeds  and  jointed  runners,  and  is  very  hard  to  eradicate  when 
once  established.  By  constant  cultivation  the  grass  can  be  kept  out, 
as  is  done  in  the  orange  districts  of  southern  California.  It  can  be 
eradicated  by  plowing  the  land  and  then  letting  it  go  dry  all  summer. 
The  roots  should  be  kept  stirred  by  cultivation  so  that  they  may  dry 
completely.  When  the  moisture  content  in  the  soil  remains  high, 
however,  the  roots  are  apt  to  live  over.  On  some  of  the  hard  Imperial 
clay  lands  Bermuda  is  grown  for  pasture.  It  makes  fair  feed  when 
alfalfa  cannot  be  successfully  grown. 

Blue  grass  (Poa  pratensis)  grows  well  during  the  winter  season 
but  does  not  endure  the  hot  weather  well.  If  care  is  taken  to  keep 
the  ground  well  soaked  it  will  live  through  the  summer  but  never  does 
well. 

Johnson  grass  (Sorgum  halipense)  has  proved  such  a  serious  pest 
especially  when  it  becomes  established  in  the  ditches  and  along  borders 
that  a  strenuous  effort  is  being  made  by  the  Horticultural  Commis- 
sioner to  exterminate  the  Johnson  grass  which  is  at  present  in  the 
valley.  It  has  been  introduced  through  seed,  but  is  at  present  con- 
fined to  about  sixty  ranches.  Two  men  are  hired  especially  to  dig 
these  patches  out  and  to  prevent  any  new  growth.  By  a  rigorous 
inspection  of  seed,  additional  importations  may  be  prevented. 

Millet  (Choetochloa  Italica). — Most  varieties  of  millet  do  fairly 
well  in  this  section.  Very  little  millet  is  planted,  however,  since  other 
forage  crops  produce  better  results.  It  is  generally  sown  during  the 
latter  part  of  the  summer  and  harvested  in  the  fall.  Frost  kills  it 
about  as  readily  as  Indian  corn.  Pearl  millet  (Pennisetum  spicatum) 
can  be  grown  successfully  in  the  spring  and  will  make  a  good  growth 
during  the  spring  and  summer. 

Orchard  grass  (Dactylis  glomerata)  can  be  made  to  grow  in 
Imperial  Valley,  but  it  is  not  suited  to  the  climate  and  its  culture  is 
no  longer  attempted. 

Para  grass  (Panicum  molle)  was  introduced  into  the  Valley  in 
1909  and  has  made  a  remarkable  growth  in  the  few  patches  where  it 
was  planted.  It  is  considered  a  bad  weed  in  moist  tropical  countries, 
although  it  is  used  as  a  pasture  grass  and  for  hay.  It  propagates 
from  the  nodes  of  the  stem  and  consequently  is  hard  to  eradicate  when 
once  started  on  wet  land;  but  in  an  irrigated  section  it  can  be  dried 
out  by  withholding  water  and  cultivating  it  down.  It  may  prove  to 
be  a  valuable  plant  for  the  hrnli  it  yiilnnf  the  valley  where  alfalfa 


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